P1114 P0420 boost comes and goes, searched everywhere [Archive] - Audi Forums

: P1114 P0420 boost comes and goes, searched everywhere

08-03-2011, 03:44 PM
Hey everyone im new to the forium but no noob in the auto game but ive searched for this everywhere and cant find a thing. I have a 2000 1.8t 5sp with 137k. I bought the car in Nov of 10' with 126k and knew the power was a little low for what it should be. Now you think for 126k it was beat up, you have no idea. This is by far the CLEANEST used B5 ive ever seen which is the only reason I bought it. 2 owner, The interior is perfect, when detailed looks brand new. The engine leaks nothing, Trans leaks nothing, has a small pinion seal leak and one torn axle boot I packed with grease and wrapped with a combo of tape, still holding today. Anyway This car was taken care of. 3-4 weeks ago my check engine light started coming on, but going away before I could get a chance to check it. After it did that a few times i finally lost all boost. I replaced the diverter valve with the upgraded TT model, and the vacuum hose on top of the valve all the way up. I checked all hoses for leaks took it out and voila, I had more power then ever, I was really excited. Then when driving I just lost all boost again. Drove home pissed let it sit not even 30 minitues. Drove it again, Boost was back, then same thing it just goes away sometimes in the middle of boosting sometimes just cruising. I usually get through the gears a few times Its also been throwing the codes P1114 and P0420, and they just come and go. CEL turns on, couple drive cycles later its off, but there is NO pattern to the CEL and the boost it seems there are totally random. I think I can fix the CEL by replacing the O2's but any iseas on the boost issue? Any help appreciated. Sorry for the novel...

08-05-2011, 11:39 AM
so much for the help I was looking for