Hi my turbo blow year is 2001 Audi a4 1.9 tdi b6 Iv changed the central piece and made sure everything was working like the vains and stuff put everything back together but when the engine is running and I rev car no power or boost with a mixture or white and black smoke from exhaust but I did checks like removed exhaust to see if cat was blocked but still no power so put that back on then tried removing the pipe to inter cooler to see if it was that but still same so I messed around and I took the two nuts off the down pipe the brass looking one going into side of engine and slightly pulled it open the power come back and I could hear the turbo looking for advice what to do as it’s first time Iv ever done anything like this mechanical