The difference between the car front oxygen sensor and the rear oxygen sensor, what is the role of the two car nox sensors?

The difference between the car front oxygen sensor and the rear oxygen sensor, what is the role of the two car nox sensors?

1. The installation location is different
The front oxygen sensor is placed in front of the three-way catalytic converter; the rear oxygen sensor is placed in front of the three-way catalytic converter.
2. Different functions
The function of the front oxygen sensor is to detect the air-fuel ratio of the engine under different working conditions, and the computer adjusts the fuel injection amount and calculates the ignition time according to the signal. The rear oxygen sensor mainly detects the working quality of the three-way catalytic converter, that is, the conversion rate of the catalytic converter.
3. The principle is different
The working principle of the front oxygen sensor is to feed back the oxygen content in the exhaust gas to the engine computer during "closed-loop control", and the engine computer corrects the fuel injection amount according to this signal; the rear oxygen sensor feeds back the oxygen content behind the three-way catalytic converter. Give the engine computer to check whether the three-way catalytic converter is working properly (good or bad).
Oxygen sensors are widely used in petroleum, chemical, coal, metallurgy, papermaking, fire protection, municipal administration, medicine, automobile, gas emission monitoring and other industries.

Extended information
There are two kinds of oxygen sensors in practical application: zirconia oxygen sensor and titanium oxide oxygen sensor. The common oxygen sensor is divided into single lead, double lead and three lead. The single-lead type is a zirconia oxygen sensor; the double-lead type is a titanium oxide type oxygen sensor; the three-lead type is a heated zirconia type oxygen sensor. In principle, the three-lead type oxygen sensor cannot be used instead.
Once the oxygen sensor fails, the computer of the electronic fuel injection system will not be able to obtain the information of the oxygen concentration in the exhaust pipe, so the feedback control of the air-fuel ratio will not be carried out, which will increase the engine fuel consumption and exhaust pollution, and the engine will experience idling instability, Fault phenomena such as misfire and surge. Therefore, it is necessary to troubleshoot or replace in time.

What does the car nox sensor do?

The function of the car nox sensor is to detect the oxygen contained in the gas (exhaust gas) discharged from the cylinder. The on-board computer controls the intake of air and fuel according to the oxygen content of the exhaust gas, so that the fuel can be fully burned without waste and pollution. while ensuring that air does not enter too much and waste valuable cylinder volume.

Expansion information:
1. The process of using the oxygen sensor: The oxygen sensor of the oxygen sensor is an important component of the closed-loop control of the fuel injection of the electronically controlled engine. In order to meet the emission regulations and improve the fuel economy of the vehicle, the front oxygen sensor is mainly used to detect the emission of the cylinder after combustion. If the oxygen content in the exhaust gas is too high, it means that the mixture is too lean and the fuel is too little. λ>1 (λ is the ratio of the actual air-fuel ratio to the theoretical air-fuel ratio). At this time, the feedback voltage of the oxygen sensor is sent to the ECU. The result of the calculation that the mixture is too lean will increase the fuel injection quantity, and conversely reduce the fuel injection quantity.

2. The oxygen sensor detects the oxygen concentration in the exhaust at any time, and feeds back the signal to the engine computer at any time. The engine computer adjusts the fuel injection amount in time according to the feedback signal. If the signal reflects that the mixture is too rich, the fuel injection time is reduced.
3. The impact of the oxygen sensor on the car: when the oxygen sensor is broken, it will inject fuel when it is not needed, but it will not inject fuel when it is needed, resulting in decreased engine power, jitter, and higher emissions. Serious It will cause the engine to knock.