System Inspection

Engine

Engine Control - P0420 Catalyst System Efficiency below Threshold (Bank 1) - System Inspection

Exhaust System Inspection

1. Visually/physically inspect the following conditions:
-Exhaust system between HO2S and Three way catalyst for air leakage, restriction and damage.
-Damage, and for loose or missing hardware:
2. Was a problem found in any of the above areas?





Rear HO2S Inspection
1. 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 ECM)
-Any road damage
2. Was a problem found in any of the above areas?






TWC Inspection

1. 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
2. Also, ensure that the TWC is a proper original equipment manufacturer part.
3. Was a problem found?