Circuit Description
The oxygen sensor monitors exhaust gas oxygen content and delivers an input signal to ECM. The ECM uses input signal to determine fuel injection system operation. Sensors include heater. DTC is set when sensor does not output a rich condition once engine is at normal operating temperature, engine speed of 1500 RPM or more, and vehicle speed is at least 25 MPH for at least 2 minutes. Possible causes are:
- Open or short in heated oxygen sensor circuit.
- Heated oxygen sensor.
NOTE:
Oxygen sensor located in front of catalytic converter is referred to as sensor No. 1. Oxygen sensor located behind catalytic converter is referred to as sensor No. 2.