Test Description

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

1. 2
   
   Inspect 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 problem is present with the HO2S 1 disconnected.