General Description

The oxygen sensor, mounted in the exhaust system, monitors the oxygen content in the exhaust gas stream. The oxygen sensor acts as an electro chemical cell, or battery, to produce a voltage in response to oxygen in the exhaust stream compared to oxygen content of the atmosphere. A lean mixture (high oxygen in the exhaust gas) produces a low voltage and a rich mixture (low oxygen content in the exhaust gas) produces a high voltage. The oxygen content in the exhaust reacts with the oxygen sensor to produce a voltage output. The voltage signal ranges from approximately 100 millivolts (0.1 volt) for a lean mixture to 900 millivolts (0.9 volt) for a rich mixture.

By monitoring the voltage output of the oxygen sensor, the PCM will know what fuel mixture command is required to the fuel injectors.

The oxygen sensor operates between 275°C (527°F) to 850°C (1562°F).

The oxygen sensor ground is located on the back of the engine block above the starter.