Diagnostic Aids

WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Malibu, and 2003 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 affect the fuel trim.
A malfunctioning Mass Airflow (MAF) sensor can cause a rich condition and set this DTC. Go to DTC P0101: MAF SENSOR PERFORMANCE .
Use a scan tool to review the Failure Records using a scan tool. If intermittent condition is suspected, go to INTERMITTENTS in TROUBLE SHOOTING - NO CODES - 3.1L CENTURY, GRAND PRIX & MALIBU article.