limp mode? no boost? check THIS hose!
 

<center><img src="http://pictureposter.audiworld.com/6285/busted_hose.jpg"></center><p>This is on a 2000 A4 1.8T. I've had a heck of a time trying to figure out why my car was going into limp mode. I replaced my diverter valve and cleaned my MAF sensor. Both things obviously didn't fix the problem. It turned out to be a vacuum leak. I have outlined the culprit hose in the picture. You can see my temporary duct tape fix on the hose. Gotta love duct tape! :) Anyway the hose is on order and cost only 7 bucks. If anyone is having trouble with your car going into limp mode give that hose a good inspection. Mine split right at the elbow.

you should put that in your sig " limp mode mod" heheh oh well glad you found it!

Yea - happened to me, too... 2x.

Wow! You'd think Audi would be able to make a decent rubber hose. Oye!

BTW, it's part No. 058 133 783 L

EPIC
 

Lol you sir are a genius i went from 9lbs to 5lbs today and i was like wtf.. Googled going in limp mode and saw ur thread. SAME HOSE SAME SPOT!!!