[maximoline]

I recently changed the valve cover and all the coils and plugs in my 2007 328i because it had a super rough idle. after that it was mainly fixed but when i turned on the car it still had a slight shudder in park. i drove on it for a few days and it persisted but wasnt anything horrible. about a month after, my car wouldnt start because the starter was stuck. we fixed it but while i was scanning it with my OBD2 sensor i got these codes

P0306- Cylinder 6 misfire
P0174- System too lean bank 2
P0171- System too lean bank 1

i looked them up and it looked like it was most likely a bad MAF sensor. the day after, i started my AC and turned on the heater, for the first time in months, because it was cold and it started smelling bad. so i turned it back to cold on full blast to try to get rid of the smell. it got worse and smoke started coming out of my hood. the service engine soon light came on so i pulled over and scanned it. the code was P00BC- Mass or Volume Air Flow "A" Circuit Range/Performance- Air flow too low. does this mean i have a bad MAF sensor? if not what could it be?

[maximoline]

The MAF sensor could also be causing the codes P0174 and P0171 right?

[Moisture]

Yes it can be a MAF sensor. But I don't hear about those failing too often.

Next step is to look around closely for vacuum leaks and check your fuel pressure. It might be an injector.

[marvinstockman]

A no brainer is to stop at the auto parts store and buy a spray can of MAF safe cleaner. Remove MAF, spray clean, and reinstall.

[320IN54]

My MAF sensor went bad and I was getting bad idling at startup and fuel mixture codes. I tried to clean it and it didnt work so I installed a new one which fixed all the problems. I have a 335i but it shouldn't be much different in terms of how they function.