Oxygen (O2) Sensor

The O2 sensor is mounted in the exhaust manifold, where it comes in contact with exhaust gases as they enter the exhaust system. The O2 sensor generates voltage according to the oxygen content of exhaust gases. This voltage will vary from .1 volt (lean condition) to as high as 1.0 volt (rich condition). Sensor will not generate a voltage signal until it has reached operating temperature. Until sensor is warmed up, ECM will adjust air/fuel mixture based upon preprogrammed tables in ECM's memory.