ok I have an 01 tt 225 and when I hit the gas and take it to 18 psi it stays then drops to 15 then it stutters. Feels like the turbo is done or giving up. I have no idea what it could be???? Could it be the N75 going bad?

 

i had a similar problem and it was due to the where the waste gate connects to hte turbo housing was rusted out and had to replace the turbo? Im pretty sure a vag com can tell you if the n75 has it opened or closed.