If you get a 3" exhaust (DP, CAT/Test Pipe, and back) then you'll get horrible boost creep if you don't port the turbo. So unless you want or can get the turbo off and port the wastegate flapper and exhaust side, then don't get an exhaust as it will cause problems. Eventually, it is a fantastic mod to get (3" turbo back), but make sure you have prted your turbo.