around 3000 RPM + i hear shuttering(like papers flapping around really loud)

[Stiki]

in nuetral i can rev and hit the limiter..
but wen im driving in any gear..and i WOT around 3000rpm it doesnt climb any faster and has this sputtering/shuttering sound.

i checked my bpv, bov, vacuum lines, i just replaced my turbo and all gaskets.

someone said they had these problems and it was the exhaust manifold to turbo bolts being loose.
i know mine arent loose because i just tightened them last night wen i R&R the turbo.

oh, and my exhaust sounds quieter for some reason..like a silencer was put on it

i no its not the turbo because i replaced the turbo due to shaft play.

any help or suggestions?

 

[Stiki]

nevermind..problem fixed..the entire insides of the cat blew out and clogged the resinator..100 dollar solution = got a straight pipe welded where the resinator was.
cars alot louder now but i dont mind, and check engine light hasn't come on yet even tho the insides of the cat are gone.