EBPV Problem?

[jake7995]

I just replaced the turbo on my 99 7.3 with a turbo off of a 2001 7.3. Now I am getting a P0476 Exhaust Pressure Control Valve Performance code. The engine sounds muffled and I can hear the jet engine sound. I did a koer test and watched the EBP valve cycle each way without a problem and the p0476 code came up. I can still build normal boost, and the power doesn't seem too much different. I warmed the engine up and I still hear the jet engine sound. I separated the exhaust from the turbo, looked in with a mirror, and saw the butterfly valve inside is open and it's hitting the stop on the outside of the housing. Is there anything other than the EBP valve that may cause the noise or cause the code. I can read the EBP sensor with my scan tool and it's reading ~13.56 and changing which I believe is normal. I also removed the sensor and I can feel exhaust coming out of it. Any thoughts on what's going on are greatly appreciated.