ok heres what my delima is... i normaly get 10 psi of boost full throttle due to no cat and a full exhaust well today for some reason id be at full throttle and i would get about 5 then after a few miles id get on it again and have full boost. same thing when id drive through the city everyonce and a while ill have sluggish boost responce and itll cut off at 5 psi then a little ways down the road itll be fine again. so thats where im at. im guessing a vacume leak but if there was a vacume leak it would boost at all correct? any help and any ideas are greatly appreciatted. 2001 a4 quattro tiptronic 1.8t