Yours works fine? Mine was running rich with a "dump Valve".(I may add it was on the engine when purchased

)
I have always been told if you have an air flow meter you shud NEVER run a dump valve.
If you want constructive advise then you should listen to what were saying.
If its not dumping enough then the spring is prob too weak maybe, is it making a noise under boost similar to a tyre with a loud puncture?? (sorry this is the best way I can describe it haha)
Sounds like the dump valve is letting air through it under boost to me.