General Description

DESCRIPTION
The Oxygen Sensor (O2S) is located in the exhaust system to detect the concentration of oxygen in the exhaust gases. The O2S acts as an electrochemical cell or battery.

OPERATION
A voltage is produced in response to the amount of oxygen in the exhaust stream compared to the oxygen content of the atmosphere. A lean mixture (high O2 content in exhaust) will produce a low voltage. A rich mixture (low O2 content in exhaust) will produce a high voltage. O2S voltage ranges from approximately 100 millivolts (0.1 volts) (high O2/lean mixture) to 900 millivolts (0.9 volts) (low O2/rich mixture).

By monitoring the voltage output of the O2S, the ECM will determine what fuel mixture command to give to the injectors.