Oxygen Sensor

The oxygen (O2) sensor is mounted in the exhaust manifold where it is exposed to exhaust gas flow. Its function is to monitor oxygen content of exhaust gases and to supply the logic module with a voltage signal directly proportional to this content.

If the oxygen content of exhaust gases is high (lean air/fuel mixture), the voltage signal to the logic module is low. As oxygen content decreases (mixture becomes richer), signal voltage increases.

In this way, the logic module is kept constantly informed of air/fuel ratio. It can then alter fuel injector "ON" time, in response to these signals, to obtain the best air/fuel ratio under any given operating conditions.