Diagnostic Aids
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
If an HO2S bank 2 sensor 1 heater circuit DTC is also set, diagnose that DTC first. An inoperative heater will slow down sensor activation time and may set this DTC.
To locate an intermittent problem, use scan tool to monitor HO2S bank 2 sensor 1 voltage with engine running at normal operating temperature. Bias voltage (450 mV) will appear on scan tool if an open anywhere in the sensor circuit exists.
Normal scan tool readings in closed loop for bank 2 will vary between 60 mV and 1080 mV.