Component Inspection

Inspect the following:
- Inspect HO2S for silicon contamination from fuel or use of improper sealant. The HO2S may have a white powdery coating and this will result in a high but false voltage signal (rich exhaust indication)
- Replace HO2S as necessary and go to next step.
Warm up the engine to normal operating temperature.
Monitor the "HO2S Voltage (B1S2)" parameter on scantool.
1. Specification: Approx. 0.6 ~ 0.7V
  
  Fig 1: Scantool Display - HO2S Voltage (B1S2) Parameter
Is the sensor's signal within specifications?
YES
1. Substitute with a known-good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
NO
1. Check HO2 sensor for contamination, deterioration, or damage. Substitute with a known-good HO2 sensor and check for proper operation. If the problem is corrected, replace HO2 sensor and go to "VERIFICATION OF VEHICLE REPAIR " procedure.