Circuit/System Testing
- Verify none of the following conditions exist:
- Lean or rich fuel injectors-Refer to Fuel Injector Balance Test with Special Tool .
- Water intrusion in the HO2S harness connector
- HO2S wiring harness damage
- Incorrect RTV sealant
- Low or high fuel system pressure-Refer to Fuel System Diagnosis .
- Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
- Fuel saturation of the EVAP canister
- Exhaust leaks near the HO2S
- Engine vacuum leaks
- Engine oil consumption-Refer to Oil Consumption Diagnosis
- Engine coolant consumption-Refer to Loss of Coolant
- If you find any of the above conditions, repair as necessary.
- If all conditions test normal, test or replace the appropriate HO2S.