Circuit Description

The heated oxygen sensor monitors exhaust gas oxygen content and delivers an input signal to ECM. The ECM uses this input signal to determine fuel injection system operation.

DTC P0133 and P0153 are set when engine is warmed up and is idling, ECM detects a response time of one second or more for sensor to change from rich to lean, or lean to rich. Possible cause is:

• Heated oxygen sensor.