Exhaust leak, failed oxygen sensor, failed catalytic converter.
Catalyst system efficiency below threshold, bank 1. Catalyst system efficiency below threshold, bank 1.
Trouble code P0420 means: Catalyst System Efficiency Below Threshold (Bank 1)
This code is for the catalyst system efficiency is below threshold
P0430 Catalyst System Efficiency Below Threshold (Bank 2)
Catalyst System Efficiency Below Threshold (Bank 2)
It's Catalyst system efficiency below threshold
P0420 Catalyst System Efficiency Below Threshold (Bank 1)
P0420=Catalyst System efficiency below threshold
Means you need a catylitic converter.
Check for exhaust leaks, check O2 sensor functionality, replace catalyst.
i m not sure what to do but what the code means is that the catalyst system efficiency is below threshold
P0420 Catalyst System Efficiency Below Threshold (Bank 1)