Check HO2S
- IG "OFF" and disconnect HO2S connector.
- Check that the HO2S is securely installed.
- Check the HO2S for contamination or damage
- Is the sensor normal?
YES
- Substitute with a known - good ECM and check for proper operation. If the problem is corrected, replace ECM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
- Substitute with a known - good HO2S and check for proper operation. If the problem is corrected, go to "VERIFICATION OF VEHICLE REPAIR " procedure.