I just bought a 1990 talon TSI this car has been. A headache since I bought but I love it and want to turn it into a beast but I'm still learning and going to school but this morning I drove my wife to work again and the road was open so I got on it a little in third gear it picked up as it should I left off around 5000-5500rpm and I saw a red light pop up wasn't sure what light it was at first and it came back on and would go away it was my check engine light when the light would come on the car would die it would not accelerate the Rpms dropped down to 1500 until the cel went away and it would pull hard again. So when I got around the corner from my house I got it on again and it was fine but not full boost. It felt like something stuck for a second and went away it was 50degrees outside but the engine was warmed up

A little background about the car the previous owner rebuilt the engine and tranny less than 1000mils on the build, it was just a stock rebuild the only thing the has done to it is a 16g turbo, and a 3in exhaust(which is disconnected from the down pipe back because the past owner bent the exhaust and it hits my driveshaft while I drive was planning on taking it to a shop haven't had time yet) but it still has stock side mount and could have bigger injectors I'm unsure though stock ecu