Check HO2S
- Inspect the front HO2S for any silicon contamination. This contamination will be indicated by a white powdery coating and this will result in a bad false voltage signal. If contamination is evident on the HO2S, replace contaminated sensor with the new one and go to next step.
- Is sensor contaminated?
YES
- Substitute with a known-good HO2S and check for proper operation. If the problem is corrected, replace HO2S and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "VERIFICATION OF VEHICLE REPAIR " procedure.