Hey guys, got a friend with a 04' e60 with the M54 in it. Throws the CEL, drives fine but stores fuel trim codes for both banks, mixture too lean. On an E46 I know its usually a disa valve, throttle boot, oil separator hoes, sometimes maf but the M54 in the E60 the intake system is different. checked the disa/intake didn't find any air leaks. was gonna try and clean the maf next. Anyone run into this issue? tia.
04' 525i Fuel Trim codes?
