Very high LTFTs

[y2k_o__o]

One thing that I would like to share is the airbox oil drain. The 20+ year old drain tube fitting is noticeably smaller that won't seal very well to the airbox after years of heat cycle.
I highly recommend to replace it no matter what just for the peace of mind.

[sapote]

My 2002 M3 (130k miles) is also having the same issues in these 2 years, same high LTFT (15-20%, but no CEL) and did smoke test and no results, so today I decided to replace all my vacuum-related lines with new BMW parts.

Bad MAF with low report data can cause high LTFT. Do a data log with obdFusion app.

[y2k_o__o]

Bad MAF with low report data can cause high LTFT. Do a data log with obdFusion app.

I also replaced my old MAF sensor with Bosch part 2 years ago, the likelihood of faulty is low but it's worth a check to swap the old one back and see. I still keep all my old sensors around in case I need them for troubleshooting