Short story...Did the MAF test, audi a4 1.8t 2001 ran 150% better with it disconnected. Bought a new MAF, plugged it in, ran like crap again.

Was just about to pull some numbers on the vag com when i was double checking the harness connected to the MAF. I noticed there are 5 wire taps at the head of the sensor connector. I have 4 connected in and i looked at the top of the cap and i saw a black wire that was disconnected? any ideas if this is wrong/right/correct/solution to my problem?

 

Thats normal i believe there's only 4 wires but there room for 5. The car will run better without a maf sensor because it has the MAP sensnor also (i think im right about that). Either way its hard to tell your MAF is bad because my car ran 150% with it unplugged and my MAF was brand new. I actually had some vacuum leaks and PCV valve issues. My car ran like complete **** before i adressed those problems and i had no check engine lights (only when i unplugged the MAF)

 

why would it run so much better with the MAF unplugged if you still have leaks? im assuming the same could be true for me. I have a new MAF and it still runs like crap and shoots a CEL. SECONDARY AIR INJECTION PUMP or something like that. i havnt pulled it since last month.

did you just look around for the leaks or did you test it somehow? my boost gauge spikes at 15 psi and holds it.....