Where is the oxygen sensor located? How to test an oxygen sensor?

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Often this device fails. Let's look at where the oxygen sensor is located in the car, how to check its performance. We will also find out the signs of a malfunction and everything about this sensor.

A bit of history

This element can be considered the most popular among all other sensors and sensors in the car. Automotive diagnostic specialists often deal with it. There were oxygen sensors before, this is not a novelty. The first lambda probe was a kind of sensitive element without heaters. The element was heated by the temperature of the exhaust gases. The heating process took some time.

As the years passed, the environmental situation around the world was constantly deteriorating. Therefore, it was necessary to take measures to tighten the harmfulness and toxicity. Requirements for cars have become tougher. At this point, the sensor began to develop and evolve. It was equipped with a special heater.

How a lambda probe works

To know how to test an oxygen concentration sensor, you need to have an idea of how the elementworks. The working part of the part is a kind of ceramic material, which is covered with a layer of platinum. This element operates at high temperatures.

Operating temperatures can reach 350 degrees or more. While the sensor is warming up to its operating temperatures, the preparation of the fuel mixture is regulated according to data received from other sensors. To warm up the sensor faster, it is equipped with an electric heater. As for the principle of operation, it is simple. Exhaust gases envelop the working surface of the sensor, which, in turn, notes the difference in the levels of oxygen contained in the exhaust and in the environment. Next, the lambda sends data to the ECU. The latter gives commands for the preparation of the working mixture.

Where is the oxygen sensor located?

So, for engines from AvtoVAZ with a volume of 1.5 liters, the lambda probe is in the exhaust system. More precisely, on the receiving tube. This element is simply screwed in from above, in front of the resonator, or in front of the spacer if there is no pre-muffler.

For 1.6 liter engines from AvtoVAZ, a different design of the exhaust system is used. So, two lambda probes are used here. Both are located on the catalytic manifold. One or two sensors are mounted on these motors. If the engine is made under Euro-2 environmental standards, then there is only one element. If under "Euro-3", then there will be two lambda probes. So on all Lada Priora cars. How to checkoxygen sensor? It is necessary to dismantle it and make sure it is working properly with the help of special equipment - a multimeter.

Why does the lambda probe fail?

The reasons why these elements fail may be different. Often this is a depressurization of the case. Breakdowns are also possible due to the penetration of external oxygen and exhaust gases into the sensor. Another common cause is overheating.

Occurs due to poor assembly of the motor or incorrect operation of the ignition system. Also, often the sensor breaks due to obsolescence, incorrect supply or unstable power supply. Mechanical damage is also possible.

Signs of malfunction

Often there are malfunctions in which the main reason is the oxygen sensor. How to check it depends on the symptoms of the malfunction. Let's consider them. The main sign that indicates that the lambda probe is faulty is changes in the operation of the motor. The fact is that after the sensor fails, the quality of the fuel mixture deteriorates significantly. Simply put, no one is responsible for preparing the mixture - the fuel system is uncontrolled. In all cases, except perhaps the last one, the sensor does not fail immediately, but gradually.

Many owners don't know where the oxygen sensor is located, how to check if it's working, etc. They don't immediately realize that the element is defective. But for experienced car owners to understand and determinewhy the operation of the motor has changed will not be difficult. The process of sensor failure can be divided into several main stages. In the first stages, the element simply stops working normally - at some moments of engine operation, the lambda probe simply does not transmit readings. Because of this, the operation of the motor is destabilized - the revolutions float, unstable idling is observed. Turnovers can fluctuate in significant ranges. This will eventually result in the loss of the correct fuel mixture ratio.

At the moment, the car may twitch for no good reason, uncharacteristic pops are heard, and the lamp on the dashboard also lights up. All these signals indicate that the lambda is failing and is already not working properly. You need to know how to check the oxygen sensor in order to fix the problem in time. Further, the work of the lambda completely stops on a cold engine. In this case, the car will in every possible way inform the owner about the presence of a problem. For example, power will drop dramatically, there will be a slow reaction to the gas pedal. Pops are heard from under the hood, the car twitches. But the most significant and dangerous signal is the overheating of the motor. If you completely ignore all the signals that are already screaming about a malfunction, a complete failure of the sensor is guaranteed. How to check the oxygen sensor, the driver often does not know. Therefore, a malfunction can cause big problems.

If nothing is done

The motorist himself will suffer first of all, as fuel consumption will increase, and exhaust gases willsmell toxic with harsh hues from the pipe. In the case of modern cars with a lot of electronics that knows how to check the he alth of the oxygen sensor, the lock is activated. In such a situation, any movement by car will become impossible. But the worst option is depressurization. The car won't move at all or it won't start. This is fraught with complete failure of the engine. In the event of a depressurization, all gases instead of the exhaust pipe will enter the air intake duct. When engine braking is performed, the probe will detect toxicity and will give negative signals. This will completely disable the injection system. The main sign of depressurization is the loss of engine power. This can be felt while driving at speed. Also from under the hood you will hear a knock and pops, a smell. In the past, motorists needed to know how to tune a carburetor. Now nothing has changed - you need to remember how to check the oxygen sensor (VAZ-2112 is no exception).

Diagnosis using electronics

It is possible to find out what condition the lambda probe is in only with the help of specialized equipment. An electronic oscilloscope is also suitable for testing. Specialists know how to check the probe in other ways (multimeter), but this way you can only find out if the element is working or broken.

Before you check the he alth of the oxygen sensor, you must start the engine. In a calm state, the probe cannot fully show its entire working picture. If there are minor deviationsfrom the norms, it is better to replace the part with a new one.

Mistakes

If there is a problem with the sensor, the car's system will do its best to report it. You can connect a special device to the diagnostic socket, and everything will be visible. The car's electronics know exactly how to check the operation of the oxygen sensor. Even VAZ cars are equipped with a diagnostic system. Errors are read from P130 to P141 - these are all lambda-related codes. Most often, messages appear that are associated with malfunctions in the heating circuits. Because of this, incorrect information comes to the ECU. You can try to find a broken wire, but it is better to replace the oxygen sensor. You already know how to test it for performance.