Oxygen Sensor: Description and Operation

This sensor provides a variable voltage of 100-900 millivolts that is actually an analog for the oxygen content in the exhaust gases. As the oxygen content increases (lean mixture), the voltage output from the sensor decreases proportionately and the oxygen content decreases (rich mixture), the voltage output increases proportionately.

The ECM uses this voltage data to control the mixture control solenoid in the carburetor to maintain an optimum air/fuel mixture. On 1981-82 models the oxygen sensor must be replaced after 30,000 miles of service. Need for this service will be indicated by illumination of the "Emission Maintenance" light on the instrument panel.


NOTE: The engine must be warmed to a predetermined temperature before the oxygen sensor voltage output is accepted by the ECM.