Oxygen Sensor: Description and Operation

PURPOSE/OPERATION
The oxygen sensor provides an input Voltage to the engine control module. The oxygen sensor is a Voltage generating device. A Voltage signal (0-1 volt) is generated by the difference in oxygen content between the exhaust gases and outside air. The higher the difference (rich mixture, low exhaust oxygen content) the higher the Voltage generated by the oxygen sensor. Smaller differences (lean mixture, high exhaust oxygen content) result in a lower Voltage generation. The engine control module uses the Voltage signal for control of the air/fuel mixture.