Oxygen Sensor: Description and Operation

Oxygen Sensor Circuit:

A heating element, located inside the oxygen sensor, aids in warm up to allow quicker closed loop operation and closed loop operation during extended idle.

The oxygen sensor is located in the exhaust system. The sensor monitors atmospheric air versus exhaust gas oxygen content to produce a voltage output. This voltage ranges from approximately 0.1 volt (high oxygen - lean mixture) to 0.9 volt (low oxygen - rich mixture). By monitoring the oxygen sensor output voltage, the computer can determine the amount of oxygen in the exhaust gas and adjust the air/fuel mixture accordingly.