Diagnostic Aids

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

A cylinder that is misfiring can also cause the misfire current counters to increment for another cylinder. Diagnose the cylinder with the highest level of misfire first.
Performing the Fuel Injector Coil test may help to isolate an intermittent condition. Refer to BASIC FUEL SYSTEM CHECKS in appropriate BASIC DIAGNOSTIC PROCEDURES article.
If the condition is intermittent, refer to INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.