Engine light stays on. Mechanic’s scope indicated a code and changed the Catalytic Converter and one Oxygen Sensor. Shortly after the engine light came on again. He changed the second Oxygen Sensor. Light came on again Both times he used his meter, the code said the problem was with the Sensor. Any suggestions for what I should check next? Could the problem be electrical (a short or faulty wire harness)?
I am guessing as to what the actual code is as you did not provide it. If the code is different please indicate it by responding in the comments.
Chrysler Code P0420
Description: Catalyst System Efficiency Below Threshold Bank 1
Probable Causes:
- Sensor or solenoid faulty
- Connector terminal contact is damaged or corroded
- Wire harness – Check harness for correct voltage, open, short to ground or short to voltage
- Update control unit software – Check for the latest control unit update
- Powertrain or Engine Control Module faulty
- HO2S sensor contamination/damaged
- Exhaust leaks or restrictions
- Catalytic converter damage
- Catalytic converter improper operation