I have a 2000 a4 1.8t quattro automatic. Just recently when I turn it on idling around 800-900 rpm idles really hard and feels like it is choking, put it in reverse or drive and let it idle and you are jerked forward an inch at a time, not rough but you can feel it pull not pull, pull, not pull hit the gas and the car runs as smooth and as quick as ever like nothing is wrong just at undere 1000 rpm. Not only that but now my car sounds like it has a blow off valve when I let off the gas. sounds like air escaping or something. Whats the deal please help.

 

simply check for air/vac leaks

 

on the way home from work today the car felt much slower then normal, flooring it the car would not rocket like it used too. I will check for air/vac leaks, could it be anything else?

 

issue fixed sure enough last time I removed my airbox to clean everything I did not put the hose in the front all the way on or did not tighten the metal ring tight enough either way I pop my hood and take a closer look only to find that there is a gaping hole between where my airbox should meet my intake. Anyway 5 minutes later everything reconnected PROPERLY!!!! and the BOOST IS BACK BABY!. Thanks By the way my check engine light is still on does this just need to be reset or something?

 

bring it to autozone to have it cleared. it went off because umetered air was getting in there since it wasnt passing through the MAF.