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Unread 01-24-2012, 08:28 PM   #7
Big Evil
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Name: Big Evil
Title: Moderator
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Join Date: Nov 2008
Location: Tempe, Az
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Your Ride: 1994 BMW 525i, 1987 325is, 1986 325
I'm hesitant to interject here, but it seems like taking a step back and looking at the system as a whole instead of a collection of parts is what is warranted at this point. Right now I would ignore the misfire and o2 sensor codes, they're more likely symptoms of the problem and not causes.

Your problem is running rich and rough, which can cause the other codes. So isolate what goes in the front of the engine, you need air (non-clogged unrestricted air filters/flow), a metering device (throttle plate) and a measuring device (MAF). The system also needs to be absolutely sealed after measuring device. So the intake runners, boots and ALL the vac lines need to be checked and if necessary smoke tested to verify there are no leaks. Then you need to be certain all the passage ways and actuators are clean and functioning (ICV, PCV etc.). Also need to be certain everything is plugged in correctly and all the connectors are seated and none of the pins have pushed out the backs of the connectors or have been stretched causing poor contact. Chances are you will find your problem in the intake metering system and your other problems will go away. I find it VERY difficult to believe all those parts went bad all at once, it just doesn't happen that way.

Careful diag will uncover your problem, there's more than likely only one problem and the rest are symptoms of that problem
Big Evil, The BMW driving monster of the American Southwest (Currently on BMW #5)
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