Hey guys, i have an 05 evo with the stage 1+ vishnu setup (xede, cams, turboback)

Until yesterday my car was running perfectly fine, then i let a guy at work drive my car and when i got it back he told me it seemed to loose power after 5k rpms. When i drove my car again It boosts fine (up to 1.3-4 bar) but as soon as I floor it or the car goes over 6k rpms you hear a weird sound and the boost drops down to almost 0.

The weird part is I dont think anything is leaking because it can hold the 1.4 okay. At partial throttle even when boost is kept under 1 bar, as soon as 6k rpms comes it dumps all the boost.
If anyone has any ideas or suggestions I would greatly appreciate their input.

Thanks in advance