1. What is oxygen sensor?

Automobile oxygen sensor is the core element of automobile electric fuel injection system (ECU) used to monitor the oxygen content in the exhaust gas of engine and feed back the signal voltage to ECU according to the data output measured by it, so as to control the amount of oil injection, make the air-fuel ratio reach the best status, improve the combustion efficiency and reduce the emission of harmful gas (such as: CO, HC and NOx).

Product structure drawing:

2. Function of oxygen sensor

The combustion process can not leave oxygen. For automobile engine, whether the combustion of the fuel is sufficient depends on A/F. The oxygen sensor used to control A/F of automobile engine is installed in the exhaust duct to test the oxygen content in the exhaust gas. According to the corresponding relationship of oxygen content and A/F, it can determine the value of A/F by testing the oxygen content. Therefore, according to the signal obtained by oxygen sensor, it can feed it back to the control system, so as to make fine adjustment on the injection amount of fuel, control A/F in the best status and reach the effect of greatly reducing the waste discharge amount and saving the energy.

The main function is embodied in the following several aspects:

Improve the combustion of the engine and reduce the emission of harmful gas;

Make catalytic converter work in the best status;

Save the fuel by 15%;

3. Common fault of oxygen sensor         

1.Oxygen sensor poisoning

Oxygen sensor poisoning is a kind of failure that always happens and is difficult to prevent. Especially for the automobiles that always use leaded petrol, even the new oxygen sensor can only work for several thousand kilometers. If it is slight lead poisoning, the lead on the surface of the oxygen sensor can be removed by continuing to use a kind of gasoline not containing lead, to make it recover to normal work. However, because of too high exhaust temperature, lead always invades inside it, blocks the diffusion of oxide ion and makes the oxygen sensor lose effect. At this time it shall be replaced.

2.Carbon deposition

Since the engine does not have good combustion, it forms carbon deposition on the surface of the oxygen sensor, or the deposit such as oil stain or dust enters the oxygen sensor, which will block or obstruct the external air from entering the oxygen sensor, make the signal output by the oxygen sensor out of alignment and ECU can not correct the air-fuel ratio in time. Carbon deposition mainly displays as the rising of oil consumption and obvious increase of emission concentration. At this time, if the deposit is cleared away, it will recover to normal work.

3.Fragmentation of ceramics of oxygen sensor

The ceramics of oxygen sensor is hard and crisp. When knocking it with hard object or blow washing it with strong air current, it may be broken and lose effect. Therefore, it shall take special care when dealing with it, and replace it in time when discovering the problem.

4.Resistance wire of heater is burnt out

For the heating type oxygen sensor, if the resistance wire of heater is burnt out, it is very difficult to make the sensor reach the normal working temperature. Hence, it will lose the effect.