OK, so I have been posting about my rough idle and how it dies after 5-10sec of start-up and I need some help. While I had the car running between 5-10 sec, I disconected (unscrewed) the MAF sensor and the car returned to normal and idled GREAT. I go back to connecting the MAF and the car dies. So I have the MAF disconnected and the car runs and drive with NO problems but the CHECK ENGINE is still on. I was 100% certain the MAF needs to be replaced but when I tested it, it seems to work fine so then I cleaned the Idle control valve(when you can hear the flap move freely inside) and still the problem. Whats going on? I still think its the MAF sensor even though I tested it

my problem was very similiar.
i would have it checked for a vacuum leak.
he dealer here locally did a general diagnostic check for $149 and found mine.
I know the dealer is expensive, but I have no trustworthy mechanic that doesn't see dollar signs when they see a bmw.
I would bet its a vaccum leak though. Everything you describe is exactly what my car was doing.

my problem was very similiar.
i would have it checked for a vacuum leak.
he dealer here locally did a general diagnostic check for $149 and found mine.
I know the dealer is expensive, but I have no trustworthy mechanic that doesn't see dollar signs when they see a bmw.
I would bet its a vaccum leak though. Everything you describe is exactly what my car was doing.

So MAF sensor is OK and everything else is PROB OK but you think its Vacuum leak?? That was my other guess b/c you can hear the leak when you have the hood open and when you're revving it? So how do I fix the vacuum leak? Thats whats causing the CHECK ENGINE.... probably right?

I had engine fault codes for MAF, both O2 sensors, Lamda control 1 and 2,
The vaccum leak was repaired, tcv gasket, and pcv gasket and plate total cost from dealer was about 1300. ouch. but car runs great now. 94 740i

I had engine fault codes for MAF, both O2 sensors, Lamda control 1 and 2,
The vaccum leak was repaired, tcv gasket, and pcv gasket and plate total cost from dealer was about 1300. ouch. but car runs great now. 94 740i

ok, what exactly is Lamda control and how do you repair a vacuum leak?

sorry forgot to say a smoke test at a local mechanic can find the vacuum leak, then you can decide if its something you can tackle. I personally didn't have the time, nor did my wife have the patience , it is her car after all, so my blood has been spilled upon the dealers lot.

I had engine fault codes for MAF, both O2 sensors, Lamda control 1 and 2,
The vaccum leak was repaired, tcv gasket, and pcv gasket and plate total cost from dealer was about 1300. ouch. but car runs great now. 94 740i

The car also sounds like my snowmobile from the exhaust, like a 70's muscle car. could that be the o2 sensors?