Function Of Oxygen Sensor

The role of the oxygen sensor is to determine whether there is excess oxygen in the exhaust after the combustion of the engine, that is, the oxygen content, and the oxygen content is converted into a voltage signal and transmitted to the engine computer so that the engine can achieve the closed-loop control with the goal of excess air factor. To ensure that the three-way catalytic converter has the maximum conversion efficiency for the three kinds of pollutants (HC, CO and NOX) in the exhaust gas, maximize the conversion of pollutant emissions and Purification.

The air-fuel ratio greatly affects the content of HC and CO in the exhaust gas. When the air-fuel ratio is lower than 14.7: 1, the HC and CO contents decrease. If the air-fuel ratio is higher than 14.7: 1, HC and CO content increased rapidly. However, reducing the air-fuel ratio results in an increase in the combustion temperature and an increase in nitrogen oxides (NOX) in the exhaust gas. Therefore, the ideal air-fuel ratio should be in the very close range of 14.7: 1. In addition, the conversion efficiency of the three-way catalytic converter is highest only in a very small area with an air factor of 1