Check Rear HO2S.
Visually/physically inspect the rear 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.
- Check for terminal tension (at the HO2S and at the PCM).
- Any damage.
Has a problem been found in any of the above areas?
YES
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
▶ Go to "Check TWC" as below.
Check TWC
Visually/physically inspect the three-way catalyst(TWC) converter for the following damage:
Severe discoloration caused by excessive temperature
Dents and holes
Internal rattle caused by a damaged catalyst
Also, ensure that the TWC is a proper original equipment manufacturer part.
Has a problem been found?
YES
▶ Substitute with a known - good TWC and check for proper operation.
▶ If the problem is corrected, replace TWC and go to "Verification of Vehicle Repair" procedure.
NO
▶ 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.
There is a memory reset function on scantool that can erase optional parts automatically detected and memorized by PCM. After testing PCM on the vehicle, use this function to reuse the PCM on the others
