Originally Posted by forlooks

I've changed the sparks, coils, fuel pump & filter, water pump (metal propeller), radiator, & radiator hoses all at the same time (@ 90,000 miles). About 500 miles later i decided changed the Vacuum hoses on my own, which is common on the M54. While changing the vacuum hoses, i cleaned my idle valve & throttle and changed the throttle gasket. Then i got the lean mixture code on the O2, after all those parts and I've cleaned my MAF twice, prior to any O2 CEL. At that point i changed the MAF (got tired of cleaning, because cleaning was more of a band-aid rather than a real fix. The O2 code went away and hasn't shown up for the past 1,000 miles. Idle is more stable, better start up and smoother acceleration. I still have an idle issue at street lights, which will be my DISA (also another common problem). I will change that next too. I rather spend money on parts/preventative rather than paying for tow.

In short, from my experience, I doubt that the vacuum is causing your O2 CEL.

Originally Posted by moyern83

forlooks,

Question for you - I have cleaned the "MAF," but the MAF that I cleaned was actually the "Hot-film air mass meter," P/N 13627520519. I was looking at realoem.com and the actual mass air flow sensor is P/N 11721438814. What is up with that? Can somebody explain that to me? I am sure it is a stupid question, but I have to ask it...

Hot-film air mass meter:
http://realoem.com/bmw/showparts.do?...29&hg=13&fg=20

Mass air flow Sensor:
http://realoem.com/bmw/showparts.do?...50&hg=11&fg=50

Originally Posted by AchtungE60

My Bank1 Bank 2 was due to my intake manifold... DISA valve. Doubt it's your O2 sensors.
Forget that code reader get some BMW tools. Look.............You're not going to get this with any other tools that I've seen.