Test Description

The numbers below refer to the step numbers in the diagnostic procedures.

1. 2  - Check the heater current with the engine at operating temperature, and allow time for the heater current to stabilize. The HO2S 1 heater current is initially higher until the sensor reaches full operating temperature.
2. 4  - A DTC fail in this step verifies the condition is present with the HO2S 1 disconnected.