The function of the sensor is to determine whether the oxygen in the exhaust gas after combustion of the engine is excessive, that is, the oxygen content, and convert the oxygen content into a voltage signal and transmit it to the engine computer, so that the engine can realize closed-loop control with the target of excess air factor; The three-way catalytic converter has the maximum conversion efficiency for the three pollutants of hydrocarbon (HC), carbon monoxide (CO) and nitrogen oxides (NOX) in the exhaust gas, and maximizes the conversion and purification of pollutants discharged.
