Diagnostic Aids

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

Fuel contamination, such as water and alcohol will effect fuel trim.
A malfunctioning MAF sensor can cause a rich condition and set this DTC. See DTC P0101: MASS AIRFLOW SENSOR SYSTEM PERFORMANCE .
Using scan tool, review Failure Records. If intermittent condition is suspected, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.