Diagnostic Aids

WARNING: This page is about a different car, the 2002 Pontiac Sunfire, 2002 Pontiac Grand Am, 2002 Oldsmobile Alero, and 2002 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.

A restricted fuel filter can supply adequate amounts of fuel at idle, but may not be able to supply enough fuel during a heavy acceleration.
Water or alcohol in fuel may cause a low HO2S 1 voltage during acceleration.
Check for an adequate amount of fuel in fuel tank.
When engine is idling or at steady cruise, HO2S 1 voltage should vary from approximately 100 millivolts to 900 millivolts. During power enrichment mode, more fuel is needed and HO2S 1 voltage should rise to more than 447 millivolts.
Check for malfunctioning or plugged injectors.