[edjack]

Stored P-codes? Monitor short-term and long-term fuel trim, via a scan tool. Both s/b in the range of +/-5%. If both are positive, and more than 5%, there are vacuum leaks downstream of the MAF.

Consider the list from doru. Report back.

 

[edjack]

The fuel trim numbers indicate the adjustment rerquired by the engine computer to keep the engine at the proper air/fuel ratio, about 14.7:1.

The short term fuel trim is an instantaneous value, based on engine load. The long term fuel trim is used to "zero out" the STFT after a period of adjustment of STFT.

As I stated, these numbers can offer clues as to what's happening. If you do not have, or are uncomfortable with, a scan tool, you'll need to find a savvy BMW indie to troubleshoot this issue.