The P0420 trouble code is associated with Catalyst System Efficiency Below Threshold (Bank 1), indicating that the catalytic converter in Bank 1 is not operating as efficiently as expected.
Catalyst System Efficiency Below Threshold (Bank 1)
Code symptoms P0420.
1. Illuminated “Check Engine” or “Service Engine Soon” light on the dashboard.
2. Decreased fuel efficiency.
3. Lack of power during acceleration.
This code is common in brands such as:: Chevrolet, Renault, Ford, Toyota, Nissan, Mercedes Benz, Honda.
Causes of the code P0420.
1. Faulty catalytic converter in Bank 1.
2. Oxygen sensor issues.
3. Exhaust leaks.
4. Engine misfire.
5. Problems with the Engine Control Module (ECM).
Code Solutions P0420.
1. Check and, if necessary, replace the catalytic converter in Bank 1.
2. Inspect and replace any malfunctioning oxygen sensors.
3. Repair any exhaust leaks in the system.
4. Address any engine misfire issues.
5. If ECM issues are suspected, consult a qualified technician for diagnosis and potential reprogramming or replacement.