It's a 2000 s4 6 spd. When I got it I pressure tested and found 3 leaks and fixed them. One of them was spider hose mess. Had to put it all back together using t fittings. The distributer piece had the top fitting broke off that goes to the n75. On the stock ecu at wot in 3 gear and up the car will go up to barely over 8 lbs and hold there great but has a sputter almost leak a fuel cut out but runs great otherwise. I've pressure tested a dozen times and the only place I've found that leaks is on the air intake tube that goes to the turbo. No where else. One run I took it on it hit about 18 on boost on the stock ecu. I shut it down and slowly went back home but couldn't find any reason why. Next time I went out after fixing nothing on it it was back to 8 and holding. I've bypassed the n75 and it doesn't sputter and runs great. With it bypassed and running on wastegate spring alone it'll boost 9. Is the n75 the problem or is something else causing it? Also put a mbc in with the n75 and made no difference. Still sputters. Checked the diverter valves last night with the thumb over the vacuum port and pushing the plunger as far in as it will go easily it falls back down far enough that it leaves only about a 1/16 of the hole open. I bought a stage 1 giac ecu from a guy and put it in. Started the car to move it and went to take it for a test run about an hour later and it would fire up for maybe a second and die. Unplugged the battery for a few and tried again and it started. Ran for 5 minutes and died. Wouldn't start back. Unplugged the battery again and it started and ran ok but only performs like a stock ecu. And it's really hot to the touch. Any body have any ideas to what my problem is. I know the giac ecu is probably bad but what about the sputtering problem?

 

This just proves how useless these forums are. Posted twice now with absolutely no help. Even tried to aquire contact info for the so called audi guros. Better off figuring it out yourself

 

Yep.. It's just totally useless. Have you checked the spark plugs? Are there any glazed plugs? Most of the sputtering issues I've ever run into have been caused by a couple of glazed spark plugs. Since you mentioned you had air leaks, this could cause a lean condition which can glaze a spark plug in short order.