Diagnostic Aids

WARNING: This page is about a different car, the 2002 Pontiac Grand Prix, 2002 Chevrolet Malibu, and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

Fuel contamination such as water and alcohol will effect the fuel trim.
A bad MAF sensor can cause a rich condition and set this DTC. Refer to DTC P0101: MAF SENSOR PERFORMANCE .
Use a scan tool in order to review Failure Records. If an intermittent condition is suspected, refer to INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.