P0420 is a Diagnostic Trouble Code (DTC) for “Catalytic System Efficiency Below Threshold (Group 1).” Its’s up to the mechanic to diagnose the specific cause for activating this code in your case.
P0420 is a Diagnostic Trouble Code (DTC) for “Catalytic System Efficiency Below Threshold (Group 1).” Its’s up to the mechanic to diagnose the specific cause for activating this code in your case.