Oxygen Sensor: Description and Operation

PURPOSE
The Heated Oxygen Sensor is a Zirconia type unit which sends a signal to the ECM in response to the Oxygen content of the exhaust stream. This is the primary signal used to fine tune the fuel injector duration.

OPERATION
If the air/fuel mixture ratio is richer than the theoretical air/fuel mixture ratio (i.e., if the concentration of oxygen in the exhaust gas is low), a voltage of approximately 1 V is output; if the air/fuel mixture ratio in leaner than the theoretical air/fuel mixture ratio (i.e., if the concentration is dense), a voltage of approximately 0 V is output.