I just recently picked up a 2005 Srt-4,but since I have been around Mustangs all of my life, I don't know absolutely everything about the Srt4's. The problem I seem to have is some kind of leak or something. When I hit the gas, and as soon as the boost gauge passes 0 and starts building boost, as you keep accelerating, you hear almost like a release of air compression from the turbo, but really loud...like a loud "shhhhhhhhhhhhhhhhhhhhhhhhhhhhh" until you let off, and then you hear a BOV, If anybody can give me clues to what this problem is that would be great!Thank you for reading my thread!~ Ill post a video up in a little bit thank you!

 

When it happens does you boost gauge jump around? If so that is compressor surge from the small turbo. If you have an aftermarket wastegate that is probably the reason.