Visually/physically inspect the HO2S for the following conditions:
- Ensure that the HO2S is securely installed.(Pigtail and wiring harness not making contact with the exhaust pipe)
- Check for corrosion on terminals and terminal tension.(at the HO2S and at the PCM)
- Front HO2S for silicon contamination. This contamination will be indicated by a white powdery coating on the portion of the sensor exposed to the exhaust stream and this will result in a but false(high) voltage signal.
- Fuel, engine coolant or oil contamination.
- Use of improper sealant.
Was a problem found in any of the above areas?
 | ▶ Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure. |
 | ▶ Substitute with a known-good component and check for proper operation. If the problem is corrected, replace component and then go to "Verification of Vehicle Repair" procedure. |
