Unfortunately, not all car owners know what a lambda probe is and why it is needed. A lambda probe is an oxygen sensor that allows the electronic system to monitor and balance the correct ratio of air and gasoline in the combustion chambers. He is able to correct the structure in a timely manner fuel mixture and prevent destabilization of the engine operating process.

This rather fragile device is located in a very aggressive environment, so its operation must be constantly monitored, since if it breaks down, further use of the car is impossible. Periodic check lambda probe will be a guarantor stable operation auto vehicle.

Operating principle of a lambda probe

The main task of the lambda probe is to determine the chemical composition exhaust gases and the level of oxygen molecules in them. This figure should range from 0.1 to 0.3 percent. Uncontrolled excess of this standard value can lead to unpleasant consequences.

At standard assembly car, the lambda probe is mounted in the exhaust manifold in the area where the pipes connect, however, sometimes there are other variations in its installation. In principle, a different arrangement does not affect the operating performance of this device.

Today you can find several variations of the lambda probe: with a two-channel layout and a broadband type. The first type is most often found on older cars produced in the 80s, as well as on new economy class models. Broadband type sensor is inherent modern cars middle and upper class. Such a sensor is capable of not only accurately determining the deviation from the norm of a certain element, but also promptly balancing the correct ratio.

Thanks to the hard work of such sensors, the vehicle's operating life is significantly increased, fuel consumption is reduced and the stability of idle speed is increased.

From an electrical engineering point of view, it is worth noting that the oxygen sensor is not capable of creating a uniform signal, since this is prevented by its location in the collector zone, because a certain number of operating cycles may pass in the process of reaching the device with exhaust gases. Thus, we can say that the lambda probe reacts rather to destabilization of the engine, which it subsequently notifies the central unit about and takes appropriate measures.

The main symptoms of a malfunctioning lambda probe

The main sign of a faulty lambda probe is a change in engine operation, since after its breakdown the quality of the fuel mixture supplied to the combustion chamber significantly deteriorates. The fuel mixture essentially remains uncontrolled, which is unacceptable.

The reason for the lambda probe to fail to operate may be the following:

• depressurization of the housing;
• penetration of external air and exhaust gases;
• overheating of the sensor due to poor-quality engine painting or improper operation of the ignition system;
• obsolescence;
• incorrect or interrupted power supply that leads to the main control unit;
• mechanical damage due to incorrect operation of the vehicle.

In all of the above cases, except the last one, failure occurs gradually. Therefore, those car owners who do not know how to check the lambda probe and where it is located will most likely not immediately notice the malfunction. However, for experienced drivers it will not be difficult to determine the reason for changes in engine performance.

The gradual failure of the lambda probe can be divided into several stages. At the initial stage, the sensor stops functioning normally, that is, at certain operating moments of the motor, the device stops generating a signal, subsequently destabilizing the idle speed.

In other words, they begin to fluctuate over a fairly wide range, which ultimately leads to a loss of quality of the fuel mixture. At the same time, the car begins to jerk for no reason, you can also hear popping noises that are uncharacteristic of the engine, and a warning light always lights up on the instrument panel. All these anomalous phenomena signal to the car owner about malfunction lambda probe.

At the second stage, the sensor stops working completely when the engine is not warmed up, while the car will signal the driver about the problem in every possible way. In particular, there will be a noticeable loss of power, a slow response when pressing the accelerator pedal and the same popping noises from under the hood, as well as unjustified jerking of the car. However, the most significant and extremely dangerous signal of a lambda probe failure is engine overheating.

If you completely ignore all previous signals indicating a deterioration in the condition of the lambda probe, its breakdown is inevitable, which will cause large quantities problems. First of all, the possibility of natural movement will suffer, fuel consumption will also increase significantly and an unpleasant, pungent odor with a pronounced hint of toxicity will appear from the exhaust pipe. In modern automated cars, in case of breakdown oxygen sensor An emergency lock may simply be activated, as a result of which subsequent movement of the vehicle becomes impossible. In such cases, only an emergency call to a tow truck can help.

However, the worst case scenario is depressurization of the sensor, since in this case the movement of the car becomes impossible due to high probability engine breakdown and subsequent expensive repairs. During depressurization, exhaust gases, instead of exiting through the exhaust pipe, enter the atmospheric reference air intake channel. During engine braking, the lambda probe begins to detect an excess of oxygen molecules and urgently sends a large number of negative signals, which completely disables the injection control system.

The main sign of sensor depressurization is a loss of power, this is especially felt during high-speed driving, a characteristic knocking sound from under the hood while driving, which is accompanied by unpleasant jerking and bad smell, which is emitted from the exhaust. Also, depressurization is indicated by visible sediment of soot formations on the body exhaust valves and in the candle area.

How to determine a faulty lambda probe is described in the video:

Electronic lambda probe test

You can find out about the condition of the lambda probe by checking it for professional equipment. An electronic oscilloscope is used for this. Some experts determine the performance of the oxygen sensor using a multimeter, however, it can only state or deny the fact of its failure.

The device is checked during full engine operation, since at rest the sensor will not be able to fully convey a picture of its performance. In case of even a slight deviation from the norm, it is recommended to replace the lambda probe.

Replacing the lambda probe

In most cases, a part such as a lambda probe cannot be repaired, as evidenced by statements about the impossibility of repair from many automobile manufacturers. However, the inflated cost of such a unit is official dealers discourages any desire to acquire it. The best way out of this situation could be universal sensor, which costs much less than its native analogue and is suitable for almost all car brands. Also, as an alternative, you can purchase a used sensor, but with a warranty period, or a completely exhaust manifold with a lambda probe installed in it.

However, there are cases when the lambda probe operates with a certain error due to severe contamination as a result of combustion products deposited on it. In order to make sure that this is really the case, the sensor must be checked by specialists. After the lambda probe has been checked and its full functionality has been confirmed, it must be removed, cleaned and reinstalled.

In order to dismantle the oxygen level sensor, it is necessary to warm its surface to 50 degrees. After removal, the protective cap is removed from it and only after that you can start cleaning. It is recommended to use phosphoric acid as a highly effective cleaning agent, which can easily cope with even the most stubborn flammable deposits. At the end of the soaking procedure, the lambda probe is rinsed in clean water, thoroughly dried and installed in place. At the same time, do not forget about lubricating the threads with a special sealant, which will ensure complete tightness.

It is very complex, so it needs constant maintenance and timely preventive maintenance. Therefore, if there is a suspicion that the lambda probe is faulty, it is necessary to immediately diagnose its performance and, if the fact of failure is confirmed, replace the lambda probe. So everything essential functions the vehicle will be maintained at the same level, which will guarantee the absence of further problems with the engine and other important elements car.

For normal operation gasoline engine internal combustion(ICE) requires a precisely dosed mixture of fuel and air supplied to the cylinders. Its qualitative composition depends on the number of engine revolutions and the degree of its warming up. On outdated carburetor engines, dosing was controlled by the carburetor; in systems with distributed injection, the proportion of the fuel mixture (TC) is controlled by electronics.

ELECTRONIC INJECTOR CONTROL SYSTEM

"Brain" electronic system The engine control unit (ECM) is an electronic unit (ECU), it reads data from numerous sensors located on the internal combustion engine. Having collected all the readings, the unit analyzes the data and, based on the results obtained, sets commands to the ignition system and injectors. The injectors set the required proportion of fuel and air in the cylinders of the internal combustion engine, the ignition distributes the spark among the cylinders and ignites the vehicle at the moment of its compression in the combustion chamber of the cylinder.

To sensors that influence high-quality composition Vehicles, in injection engines, first of all, there is an air flow sensor (MAF) or an absolute pressure sensor (MAP, or it is also called a MAP sensor). It should be noted that the VAZ 2108-15 still uses a mass air flow sensor, although in more modern systems MAP has been installed for a long time.

OXYGEN SENSOR

Another sensor that monitors the composition of the fuel mixture and also affects fuel consumption is the lambda probe, otherwise known as an oxygen sensor. The purpose of this device is to determine whether unburnt oxygen remains in the exhaust gases of the internal combustion engine. It should be noted that a vehicle that has not completely burned out contains a large amount of CO, which is harmful to the environment.

What is the principle of operation and design of the lambda probe? Of course, DBP or MAF calculates required composition TC for a certain number of engine revolutions, but the performance of injectors may vary somewhat depending on their condition, for example, injectors may become clogged over time. In addition, the quality of Russian gasoline is not always at the proper level, and bad fuel usually does not burn completely. The lambda probe sensor works on the principle feedback– based on its readings, the exhaust gas recirculation system distills unburnt fuel into the intake manifold, and the vehicle combustion process occurs more efficiently.

Commands the ECU recirculation system. As a result:

• The toxicity of exhaust gases is reduced;
• Fuel consumption is saved;
• Ensures more complete combustion of the vehicle.

The basis of the lambda probe is a ceramic element, coated on both sides with zirconium dioxide. The sensor electrodes are in contact with the exhaust gases. At different concentrations exhaust gases create a different voltage on the probe electrodes, which is recorded by the ECU. When the oxygen content is low, the voltage at the sensor is higher.

There are two types of lambda probes - narrowband (two-point) and broadband. The second type of device has more accurate readings; sensors show not only signs of enrichment or depletion of the vehicle, but also its qualitative composition. The price of oxygen sensors also differs - broadband ones are much more expensive than two-point ones.

The VAZ 2114 oxygen sensor on a 1.5-liter engine is installed on the exhaust pipe of the muffler in the exhaust gas system. With a 1.6 liter engine, two lambda probes are provided - one is mounted on the top of the exhaust manifold, the second is immediately behind the catalyst in the area where the exhaust pipe is mounted.

It should be noted that many foreign cars can be equipped with not only two, but sometimes three or four lambda probes. As a rule, these are luxury cars, for example, Nissan Maxima. Large quantity sensors allows you to reduce the toxicity of exhaust gases and use fuel more economically.


The lambda probe begins to work at a temperature of about 350 degrees Celsius, therefore, to quickly put it into operation, many device circuits are equipped with an additional heating element. A sensor without a heater usually has one or two power wires; with a heating element there may be three or four wires. The wires must have good thermal insulation, since the heating temperature of the exhaust system is very high.

FAULTS - CAUSES AND SIGNS

The VAZ 2114 lambda probe has a certain service life - on average, the device can operate for 80-160 thousand km (calculated by the mileage of the car). But depending on various factors, it may fail earlier. This happens for the following reasons:

• Poor quality gasoline;
• There is a waste of oil in the engine, because of this, oil deposits form on the sensor (coking occurs);
• If the ignition fails, popping noises occur in the muffler, destroying the oxygen sensor on the VAZ;
• External influences - impact from an accident, liquids or oil entering the contacts of the device.

What may be signs of a malfunction of the VAZ 2114 oxygen sensor:

1. Fuel consumption increases;
2. The CheckEngine engine diagnostic lamp lights up on the instrument panel inside the car;
3. Difficulties during acceleration of the car, loss of power;
4. Engine adjustments, popping noises in the intake manifold and muffler.

But these same signs may indicate other malfunctions, and there are many reasons for this. For example:

• The air flow sensor does not work;
• Non-functional spark plug;
• High-voltage wires are pierced to ground;
• Weak compression in the engine cylinders;
• Problems with the ignition module.

HOW TO CHECK THE LAMBDA PROBE

If there are signs of a faulty lambda probe, you should first make sure it is faulty before replacing it. First of all, you need to check the ECM for possible mistakes. Errors are checked using computer diagnostics (for example, on an Ascan scanner) or using an on-board computer, if it is installed on the car and has the ability to read errors.

By the error code you can determine what malfunction has occurred in the system. For example, error 0135 means a malfunction of the lambda heating element, and 1102 means low resistance sensor Wire breaks in the circuit often occur, this is indicated by error 0140. The lack of power at the sensor connector is checked using a voltmeter. With the ignition on, connect the probes of the device:

• Minus – to the mass (to the engine);
• Plus - to contact “B” on the connector.

The voltmeter should show a voltage of 12 V. If it is missing, then there is an open circuit in the circuit. A lower voltage indicates a discharged battery. It is possible that the contact in the plug has oxidized. Cleaning the contacts in this case solves the problem.

DISCONNECTING THE SENSOR

Many car owners ask the question, what will happen if you disconnect the lambda probe from the ECM circuit, and how to disconnect the oxygen sensor? The answer is simple - with the lambda disabled, the control unit will use the standard data of the program embedded in it, and fuel will be consumed almost as much as with a faulty sensor. On average, consumption will increase by 2-3 liters relative to engine operation with a working lambda probe. And disconnecting the sensor is very simple - you just need to disconnect the plug with the wires that fits the probe.

REPLACEMENT

Replacing the oxygen sensor is very simple. Before carrying out work, it is necessary to cool the engine if it has been running. First of all, the sensor plug is disconnected, then it is unscrewed with a wrench.

Sometimes the lambda probe gets very stuck and cannot be moved. If the sensor still needs to be replaced, you can try tapping it seat– around the thread.

As a rule, this method helps to unscrew a part that cannot be removed. If the lambda does not unscrew, you need to tap again and again. As a result, the sensor is still removed.

CLEANING

If the oxygen sensor does not work, there is no need to rush to throw it away. Often, due to oil waste, carbon deposits form on the ceramic electrodes. You can try to remove the deposits, but don’t use them metal objects or sandpaper. To clean carbon deposits, use rust removers, for example, WD40. Perhaps the performance of the lambda probe will be restored.

The main symptom is a sharp increase in fuel consumption (the increase is up to 12 liters).

Another indication of its incorrect operation is the instability of the power unit at idle.

The following errors are generated by the on-board computer if the oxygen probe has flown:

• P0130 – incorrect readings;
• P0131 – weak signal;
• P0133 – slow sensor response;
• P0134 – data is not received at all;
• P0135 – breakdown of the probe heater;
• P0136 – short circuit.

In all cases, first of all, they begin to look for a broken wiring, and only if it cannot be found, they begin to replace the probe.

Why does the sensor break?

There are many reasons for accelerated wear. The main problem is low-quality gasoline with a high content of heavy metals. They form a lot of soot, which quickly covers the electrodes.

Worn oil scraper rings and caps also harm it. Because of this, lubricant often gets into the fuel and then into the exhaust pipe.

• supply of an incorrectly composed fuel-air mixture, which is caused by the failure of other sensors;
• unadjusted ignition timing - this leads to overheating of the catalyst.

Removing and installing the sensor

Before replacing, be sure to disconnect the battery by removing the negative cable. If this is not done, then any short circuit, even short-term, will lead to equipment damage or, in best case scenario, to blown fuses.

If your car has a 1.5 liter power unit, then install it on inspection hole(working with a jack is very inconvenient). After that:

• turn it out spanner wrench probe;
• remove it from the socket;
• carefully pull the wire connector out of the terminal;
• install a new node.

In cars with a 1.6-liter engine, the sensor is located differently. Moreover, in models that came off the assembly line, in last years There are already 2 of them, on the earlier ones there was only one. Here, in order to remove the additional probe, you will have to climb into the engine compartment. Be sure to remove the top cover of the motor, otherwise you will not be able to get to the exhaust manifold. Further:

• twist the sensor with a key;
• pull out;
• disconnect the cable from the connector;
• we install a new one in place.

The second probe is located as described above, that is, to dismantle it you will need to put the car in a pit.

Is it possible to repair an oxygen probe?

Any actions aimed at restoring a obviously broken control device are pointless. It’s another matter if there is a loss of contact or a break in the wire, but the sensor itself generally works.

Some craftsmen still remove soot from the electrodes. To do this, the probe is dismantled and placed for a short time in aviation gasoline or white spirit. After a few minutes, it is removed and wiped with a soft cloth.

When purchasing a new item, give preference to one that has additional heating. Such a probe begins to work correctly already at a temperature of 300 degrees, which ultimately ensures more stable operation of the engine.

At the same time, it is impossible to install conventional ones on cars that were originally equipped with forcedly heated oxygen sensors, unless certain changes are made to the circuit.

To make the replacement procedure easier, it is recommended to warm up the engine a little before it. In this case, warm exhaust pipe expands slightly and, accordingly, twisting the probe will be much easier. Just remember to wear thick gloves to avoid getting burned.

If you are not sure which sensor you need, take the old one with you to the store. The seller will be able to easily select the appropriate option.

This video will give you a better idea of ​​the process of replacing the oxygen probe:

VAZ-2114 is a very common car in Russia and the CIS countries. This car is loved not only for its price, but also for its high maintainability. Almost any component in a Lada can be replaced with your own hands. The VAZ 14th model is a continuation of the Soviet “nine”. However, besides appearance, the main difference was new type injection - injector. Such a system requires not only injectors and another fuel pump, but also all kinds of sensors. Based on them, the electronics subsequently prepares a combustible mixture. One of these elements is the VAZ-2114 oxygen sensor. Symptoms of malfunction, replacement and operating principle are further in our article.

Characteristic

What is this element needed for? Another name for it is lambda probe. This is a sensor that monitors the level of oxygen concentration in the exhaust gases. Next, the lambda value is sent to the electronic control unit. The latter, if necessary, adjusts the air-fuel mixture supplied to the cylinders.

This sensor is found on all fuel-injected cars that are equipped with a catalytic converter and comply with environmental requirements Euro-2 and higher. These include the VAZ-2114 with 8 valves. The oxygen sensor does not reduce the level of toxic substances, as many people think. He just takes measurements. And the toxicity of gases is affected by the catalyst. It is he, thanks chemical reactions, converts lead and other metals into harmless oxides and water.

Design

The VAZ-2114 oxygen sensor is designed quite simply. It consists of several elements:

• Protective layer.
• Sensitive element.
• Protective casing (there are several of these in the sensor).
• Positive electrode.
• Sealing element.
• Negative electrode.

All this is contained in a small metal case.

Where is it located?

On the 14th Lada, this element may be in different places. It all depends on the type of engine and year of manufacture of the car. So, on old one and a half liter engines with an eight-valve head, the VAZ-2114 oxygen sensor is located on top of the intake tube. The latter goes directly to the exhaust manifold. It is quite difficult to get to this element, motorists say. The sensor is accessible only from below. To do this, the car must be driven onto an overpass or inspection hole. As for new VAZ-2114 cars, the oxygen sensor is installed in top part exhaust manifold.

This arrangement is for all cars that come with a 16-valve head and two camshafts. This sensor can be detected immediately by opening the hood. It can be accessed from here. When replacing, there is no need to drive the car onto a lift or pit. It is enough to have a key of the appropriate size.

How does it work?

This element features a ceramic tip. The latter has a zirconium dioxide coating. Measurements are made using the electrochemical method. The essence of the work is extremely simple. One side of the electrode comes into contact with the exhaust gases, and the other with the atmosphere. With different concentrations of O 2 in the atmosphere and exhaust gases, a voltage is generated at the tip of the electrode. Its value depends on the concentration of O 2 in gases. The higher it is, the lower the voltage indicator. If a rich fuel-air mixture enters the cylinders, the system will be overfilled with oxygen and the lambda value will decrease. Conversely, if a lean mixture enters the chamber (where there is less than 14 kilograms of air per kilogram of gasoline), the lambda will be high. Ideal valueλ - unit.

note

Job ceramic element possible only after reaching a temperature of 300 degrees Celsius. Before this, the electronic engine control unit is guided by the average lambda value. In this case, more fuel enters the cylinders than necessary. But as soon as the car exits the warm-up mode, the mixture concentration will return to normal.

Symptoms of a problem

The VAZ-2114 oxygen sensor may fail. At the same time, the driver will notice that the yellow “Check Engine” lamp lights up on the instrument panel.

Due to the fact that the electronic control unit will not receive the correct lambda value, the engine will always operate in warm-up mode. That is, a lean mixture with a high content of gasoline is deliberately supplied to the cylinders. This is noticeably reflected in fuel consumption. Also, if the oxygen sensor malfunctions, the VAZ-2114 may stall while driving. Idle speed will be unstable. And when accelerating, the driver will feel characteristic jerks and jolts. Another sign indicating a malfunction of the oxygen sensor on the Lada is an increased concentration of toxic substances in the exhaust gases. But, as a rule, it is quite difficult to determine this by eye. To do this, you need to use a special measuring device.

Computer diagnostics

By checking the VAZ-2114 oxygen sensor in this way, we will be able to accurately determine the malfunction due to which the lambda probe has become unusable. So, we need a multi-brand scanner, phone or laptop. We connect to the diagnostic connector and turn on our reading device. To perform diagnostics, you need to turn on the ignition of the car. Next, we scan for errors. If the lambda probe on a VAZ fails, you can see the following error codes on the screen:

• P0130. Indicates an incorrect sensor signal.
• P0131. This is an excess of the oxygen concentration level in the exhaust gases.
• P0132. Indicates low oxygen levels. As a rule, such errors occur during diagnostics with the engine running.
• P0133. This code indicates a slow or weak sensor signal.

If the probe does not receive a signal at all, the diagnostics will display the following error: P0134. In this case, it is recommended to check the integrity of the contacts that go to the sensor.

Why does it fail?

There may be several reasons for the malfunction of the VAZ-2114 oxygen sensor. The most common is natural failure. This sensor contains a certain resource. Unlike foreign cars, where the lambda probe lasts for 100-120 thousand, on the Lada the sensor lasts no more than 80 thousand kilometers. Most VAZ-2114 cars in use today have long passed this period. But the sensor can break for other reasons. For example, this is a violation of the tightness of the contact of the sensor with the collector body. As a result, the device cannot receive a reliable signal. The element may also fail due to overheating of the sensitive tip. The next cause of malfunction is clogged contacts. Moreover, it is precisely inner part, which is located in the exhaust manifold. What causes the sensor to become dirty? The reason may be the use of low-quality gasoline or increased oil consumption. The latter enters the combustion chamber and comes out with soot. Some of the carbon deposits settle on the exhaust manifold tube, including the lambda probe.

Also, the cause of carbon deposits can be a breakdown of the cylinder head gasket. Because of this, antifreeze comes out along with the exhaust gases (as is known, with such a malfunction the gases become white shade).

Which one should I install?

Which oxygen sensor for the VAZ-2114 is worth buying? Note that for the second generation Lada Samara there are two types of sensors. Old cars with 1.5 engines and an eight-valve cylinder head have sensors with code 0 258 005 133.

And models that were produced after 2004 were equipped with elements with code 0 258 006 537. What is noteworthy is that both lambda probes are produced by Bosch (at least that’s what it says on the label). The cost of a new sensor is about 1.2-1.8 thousand rubles.

DIY diagnostics

It is impossible to determine the performance of this element “by eye”. As a last resort, we can visually check whether the wires fit into it and whether they are broken at all. But most often the internal sensitive element of the lambda probe fails. Therefore the most correct method- this is checking the VAZ-2114 oxygen sensor with a multimeter. This device can be bought at any hardware store for 300-500 rubles (in extreme cases, order via the Internet). How to check the oxygen sensor on a VAZ-2114? During diagnostics, we need to find out the voltage of the lambda probe. Therefore, we switch the multimeter to voltmeter mode. Next, we connect the terminals of the device to the sensor. The negative probe of the multimeter is connected to ground, and the positive probe is connected to connector B of the lambda probe. In this case, the sensor itself does not differ from the on-board network. What needs to be done next? Then turn on the ignition and look at the instrument readings. Ideally, the voltage of the VAZ-2114 oxygen sensor should correspond to 12 volts. Simply put, the value at these pins will be identical to the battery charge. If the number is less than 12 volts, then there is an open circuit in the circuit. The sensor itself may be working properly, but the voltage does not reach it. in full or absent altogether.

For more accurate diagnostics of the sensor, you can check the sensitivity of the working element. How to do it? To work, we need the same multimeter. However, we will connect to pin “C”. This is where we connect the negative contact of the multimeter. And we connect the positive probe to contact “A”. We turn on the ignition in the car and look at the readings. Ideally given value should be 0.45 V. The error is no more than five percent. If the value is lower than 0.42, it means the element has become unusable and needs to be replaced.

Recovery

Is it possible to restore a broken sensor? This can be done only in one case - if the cause of the malfunction is poor contact and the sensor itself is working normally. You can also try removing the carbon deposits inside. But to do this, you need to take the sensor out and lower it into an aggressive environment (white spirit or gasoline). Please note: do not use sandpaper, needle files or other rough objects for cleaning. To avoid damaging the tip, use a soft cloth soaked in solvent. By treating the sensitive element with white spirit, you can restore the functionality of the sensor. But it is not a fact that after cleaning it will take accurate measurements. Ideally, this element should be changed entirely. Fortunately, the operation is simple, you can do it yourself. We’ll tell you exactly how below.

How to make a replacement?

It is worth noting that the sensor is screwed directly into the exhaust manifold. And since it’s always here high temperatures, threaded connection may stick. To make it easier to unscrew the sensor, you need to stock up on universal lubricant VD-40 or a “liquid wrench”. Having treated the joints with it, you can begin to work. Please note: the replacement operation must be performed on a cooled engine, since the temperature of the manifold and exhaust pipe is more than two hundred degrees.

If it's an old 8-valve Lada, we need access to the bottom. We drive the car into the pit and look for the sensor output. Sometimes it is hidden under metal protection. If there is no special hole in it, it is better to remove the entire shield. After this, disconnect the plug with the wires and start unscrewing with a 22 key old element. If it is tight, try tightening it and then unscrewing it again. Periodically treat the threads with multi-purpose lubricant. This makes it much easier to unscrew stuck elements. After this, take the part out and install new element. You need to tighten it with a little force - about 44 Nm. After this, we connect the plug with the contacts and start the motor. It should work stably, and the “Check Engine” light should disappear on the instrument panel.

As for 16-valve VAZ-2114 cars, the oxygen sensor here changes in a similar way. The only exception is its location. Since the sensor is screwed into the exhaust manifold and not into the exhaust pipe, it is accessible from the hood.

An oxygen sensor (another name is a lambda probe) is a device designed to measure the oxygen level in a mixture of exhaust gases. With its help, the proportions of oxygen and fuel in the mixture are adjusted, which ensures maximum engine efficiency and reduced fuel consumption.

Description, principle of operation

The basis of the sensor design is a solid gas-tight electrolyte, which is ceramic material from zirconium dioxide and yttria. Internal and external surfaces The elements are covered with porous platinum, which acts as electrodes.

The device is installed in the exhaust manifold, where it is heated by exhaust gases to a temperature of 300-400 degrees. The heated sensor becomes conductive for oxygen ions and begins to function.

The element becomes most effective and reliable at temperatures above 350 degrees.

The lambda probe compares the oxygen concentration in the exhaust gases with the oxygen content in the internal chamber. The internal chamber of the device is isolated from the exhaust flow and communicates with the surrounding air, which is used as a control gas. Due to the receipt of different oxygen concentrations, a potential difference occurs, which is transmitted in the form of signals to the engine control system.

In stoichiometry, lambda is the ratio of the actual air content to the desired one. If lambda is 1, then the actual amount of air is equal to the required amount. Lambda >1 – lean mixture, lambda Design features oxygen sensor VAZ 2114

The oxygen sensor begins to work effectively only when heated to 350 degrees, so at first such devices were installed closer to the exhaust manifold. The modern lambda probe has a built-in a heating element, which allows you to get back to work faster.

The VAZ 2114 oxygen sensor includes the following elements:

• solid ceramic tips with holes for sampling exhaust and atmospheric air;
• heating element located inside the tips;
• electrical signal current collector;
• a metal case with threads used to install the sensor (the case houses all structural elements, except for the sensitive parts of the tips);
• a set of wires that connect to the computer.

Devices with a set of wires are a modern version of an oxygen sensor, which is called a four-wire one (two white wires are the contacts of the heating system, the black wire is the signal wire, the white or black wire with stripes is the “ground”).

How often to change the oxygen sensor

The VAZ 2114 lambda probe has a significant resource - 80-160 thousand km, which depends on the quality of the fuel mixture and other important factors. According to the requirements of the service book, the sensor needs to be replaced after a mileage of 60-80 thousand km. This is due to the fact that the lambda probe wears out over time, which leads to loss of sensitivity and, accordingly, deterioration in efficiency.

Signs of a malfunctioning oxygen sensor

The main symptoms of problems with lambda probe 2114 are presented below:

• significant fuel consumption under standard conditions;
• unstable idle;
• deterioration of the dynamic characteristics and power of the car;
• signals on the on-board device indicating errors in the operation of the oxygen sensor (errors P0130, P0131, P0134, P0135, P0138, P1102, etc.);
• crackling in the catalyst zone when the engine is turned off;
• a specific smell that appears due to large quantities of unburnt gasoline entering the catalyst.

If all of the above symptoms occur, the oxygen sensor will most likely need to be replaced. A device of a certain type is selected taking into account the year of manufacture of the car, since one- or four-wire sensors can be used.

Is it possible to simply turn off the sensor?

Some car enthusiasts are interested in the question of whether it is possible not to change, but simply to disconnect the lambda probe on the VAZ 2114. Experts say that the procedure itself is quite simple, but not desirable. After turning off the oxygen sensor, the ECU will switch to approximate parameters, supplying fuel for injection in average values.

This will lead to destabilization of engine operation, loss of dynamics, increased fuel consumption and deterioration of the properties of exhaust gases. In addition, the on-board computer will start to generate an error due to the absence of a sensor, so it will need to be re-flashed using chip tuning. Therefore, it is better to install a new sensor.

Causes of malfunction

Above, data was given regarding the service life of the lambda probe, which is in the range of 80-160 thousand km.

In general, the service life of the oxygen sensor is determined taking into account various conditions car operation:

• low quality fuel mixture. The content of large amounts of lead and iron in the exhaust gases leads to accelerated wear of the sensor electrodes;
• outdated or damaged oil scraper rings, caps, the use of which causes oil to penetrate into the mixture and, accordingly, the exhaust system;
• the appearance of pops in the exhaust system, which cause destruction of the sensor surface;
• overheating of the device, which occurs due to the supply of unrefined fuel (clogged cleaning filters);
• resource development;
• mechanical damage to the oxygen sensor when the car is moving.

In order to create optimal conditions To operate the oxygen sensor 2114, you must comply with following rules: use fuel recommended for VAZ 2114, do not fix the sensor with silicone sealant, check the quality and certification of additives.

Also, do not treat ceramic tips with chemically active liquids, allowing the exhaust system to overheat, preventing the accumulation of unburnt fuel (the operating temperature of the sensor does not exceed 950 degrees).

Repair, replacement

The condition of the lambda probe is first checked on a measuring device, since if the contacts in the overheating line are damaged, the device can be repaired. If there is carbon deposits on the sensor, and the potential difference on it does not differ significantly from the permissible values, then it is worth cleaning.

Since the device operates under conditions aggressive environment, it is advisable to check it every 15-20 thousand. The performance of the oxygen sensor on the VAZ 2114 is tested using accurate measuring instruments. The lower signal level of the device should be 100-200 mV, the upper – 800-900 mV.

Carbon deposits prevent oxygen from being trapped, resulting in distorted data being sent to the ECU. It is necessary to warm up the sensor very much and immediately cool it down sharply, after which the deposit will crack and can be easily removed with a soft brush.

To clean the surface of the sensor, you can use special remedy to dissolve rust, in particular phosphoric acid. Do not use sandpaper, as it will erase the coating on the ceramic.