Oxygen (O2) Sensor

Oxygen sensor is mounted in exhaust manifold or exhaust pipe, where it contacts exhaust gases. The O[I2] sensor generates voltage according to oxygen content of exhaust gases. Voltage will vary from .1 volt (lean condition) to as high as one volt (rich condition).

Sensor will not generate a voltage signal until it reaches operating temperature. Sensor sends voltage signal to ECM, which uses it to obtain correct emissions by adjusting air/fuel ratio. Until sensor is warmed up, ECM adjusts air/fuel mixture based upon preprogrammed tables in ECM memory.

On Prizm GSi, Storm GSi and Tracker models, a heated oxygen sensor is used. This sensor works the same as the non-heated sensor except the oxygen sensor is heated for more precise determination of exhaust gas oxygen concentration.