DTC P0420 BMW
Catalyst System Efficiency (Bank 1) Below Threshold
Catalyst System Efficiency (Bank 1) Below Threshold
Description
Engine started, battery voltage must be at least 11.5v, all electrical components must be off, parking brake must be engaged (to keep daytime driving lights off), automatic transmission selector must be in park, the exhaust system must be properly sealed
Cause and Solution
Air leaks at the exhaust manifold or in the exhaust pipes
Catalytic converter is damaged, contaminated or it has failed
ECT CHT sensor has lost its calibration (the signal is incorrect)
Video Guide
Diagnostic Info
- DTC Code: P0420
- Brand: BMW