Will spraying with carborator cleaning spray around suspected areas show a change in engine reving when a leak is present? Or are these cars too electronically controlled and this method will not work?
From what I've been reading it seems that I have a fixable problem given that the source is most likely around the air intake (top engine region).

Hey weasel, thanks for your posts I appreciate the help:thumbup: . I've been searching this forum as well as some others for an explanation for my SES light. It seems hard to track down the leak but im trying by doing as many searches as I can and reading a bunch of posts. If im lost for an explantion tomorrow, I'll post again.

Thanks again;)

You guessed it right, it is too controlled to pick up a change in revs before it compensates for it... the way we detect it like that at the shop is with it hooked up to the GT1 we look at the upstream O2 sensor voltages. They normally switch in the 0.2 to 0.8 range, but when you spray on the leak they peg at 0.8 for a couple seconds. Other than that we use a smoke tester just pumping the engine full of nitrogen smoke looking for where it comes out.

In an attempt to chase down an air leak I'm going to replace #2 in the diagram since it was misplace at some point and became warped. This could or could not be the source of the error. I'm wondering if there is a leak here--could this be enough be causing the lean code? While im at it i will be replacing #8 also

http://www.realoem.com/bmw/showparts...=13&fg=15&hl=6