Diagnostic Aids

WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

The most likely cause for this DTC is a deteriorated or contaminated HO2S 1.
Depending on the state of HO2S deterioration, this code may not reset or may be very difficult to reset.
If the HO2S deterioration is significant enough, other HO2S DTCs may set or be present in concurrence with this DTC.
Attempt to compare the activity of both of the affected bank HO2S 1 and HO2S 2 to the known good bank using the live plot feature of the scan tool. Operate the vehicle under various load and vehicle/engine speed conditions. Look for any indication of improper operation or contamination of the affected bank HO2S 1 or HO2S 2.
If necessary, refer to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 2.2L & 3.0L VUE article.