BMW Repair: common obdII codes, fuel mixture, emmissions

Question
"hi, & how are you?
what are the most common obdII codes for any  BMW  "CHECK ENGINE"
usally pops up at dash board.

1-what are the most common trouble codes?
2-what/why is the reason?
3-how to diagnost them?

my questions are long & involve a lot info
any information is highly apprciated or web
thank you!"


Answer
Asif, Anytime emmissions are increased to 1.5 times legal limit the check engine light is illuminated. Anything that can affect powertrain operation will cause the Light. Most common are Fuel mixture adaptations, Map-themostat, O2 sensor, Camshaft sensor, Evaporative system, and Misfire faults. I can't make you a Bmw Diagnostic Tech by answering three questions. What are your faults? Maybe I can help.
-Evan