Diagnostic Aids
WARNING: This page is about a different car, the 2002 Pontiac Sunfire and 2002 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
An intermittent could be the result of a poor electrical connection, moisture in electrical connector or wiring, rubbed-through wire insulation, or broken wire inside insulation.
Check for the following conditions:
- A poor electrical connection or a damaged harness. Inspect the PCM harness for an open in the HO2S 2 signal circuit. Check for improper mating, broken locks, improperly formed connectors, damaged terminals, poor terminal-to-wire connection or damaged harness.
- Observe the HO2S 2 on the scan tool while moving the related electrical connectors and the wiring harness with the ignition switch ON. If the malfunction is induced, the HO2S 2 display will change. This test should help to isolate the location of the malfunction.
Obstruction of the air reference and degraded HO2S 2 performance could result in any attempt to repair the HO2S harness or connector.
The HO2S 2 must have a clean air reference in order for the HO2S 2 to function properly. This clean air reference is obtained by way of the HO2S 2 wires.