Ok to start this off I have a 2001 Audi a4. Cars been acting up really bad as in ruff idling and psi staying where it's suppose to be and all of a sudden it'll just go to 4 and won't pass that at all. Few things I've thought this was at first such a fill filter changed that, spark plugs changed, all new vacuum hoses, new injector rings, lubed wast gate, lubed n75 valve, DV lubed and clean, bypass lubed and clean, Jeeze trying to remember what else I've done. Cleaned all intercooler hoses, intercooler cleaned, and I believe the last thing is cleaned the throttle body and also sea-foamed the intake manifold. And the weird part is when I was doing the vacuum lines I forgot to plug in the mass air flow sensor plug into the mass airflow sensor and it ran amazing! No rough idling boost was steady at about 9psi until the check engine light came on so I plugged it back in and now just running crappy again. I'm so lost now and have no idea what to do my buddy told me to unplug the battery and replug it in once I wake up. Any help or suggestions would be wonderful. I really don't want to have to take it to the dealership.


Thanks
Rick

 

Forgot to add its the 1.8t

 

Sounds like a dirty MAF from the sequence you describe. Sometimes oil from K&N filters can ruin the MAF, so maybe something in your cleaning process did same. I have never mucked with one, but try and clean it or (ughh) replace it. Also, posting this in the A4 section might get you more advice.