Oxygen Sensor: Testing and Inspection

Oxygen Sensor Diagnosis
Diagnose the Fuel Control Heated Oxygen Sensor (HO2S 1) is diagnosed for the following conditions:

^ A Slow Response.
^ An Inactive Signal (output steady at bias voltage-approx. 450 mV).
^ A Signal Fixed High.
^ A Signal Fixed Low.

Diagnose the Catalyst Monitor Heated Oxygen Sensor (HO2S 2) is diagnosed for the following functions:

^ The Heater Performance (time to activity on cold start)
^ A Signal fixed low during steady state conditions or power enrichment (hard acceleration when a rich mixture should be indicated).
^ A Signal fixed high during steady state conditions or decel fuel mode (deceleration when a lean mixture should be indicated).
^ An Inactive Sensor.

For further Oxygen Sensor testing and diagnostic charts, refer to Computers and Control Systems / Testing and Inspection. Testing and Inspection