P0420 BMW -

Question

my 2004 bmw 645ci has a p0420 code .Its the only code that comes up..it not the BMW scanner but does it least let you know if you have a misfire or o2 senor is bad.It runs really good showing no signs of hesitation or any thing like that..so what in the world can it be..this driving me nuts ..my inspection is coming up and it i need this enigine light off..I really dont think its the cataylatic converter..

Answer 1

HI there,

This code is for a catalytic converter issue on bank 1. This is usually a result of either a faulty rear O2 sensor or a problem with the converter itself. If the engine is running normally, then the issue is the converter in most cases.