Boost gauge acting funny please Help

[1wickedGST]

ok so here is the problem, when i git about 5k rpm at WOT my guage needle starts bouncing around between 8 and 10 psi. Also when this is happening my car doesnt pull very hard to redline (it takes it a while even in first gear) my mods as of right now are a K&N filter MBC turned down to zero (it was causing a huge vacume leak when i had it at 12-15 lbs) and that's it. Could these be signs of boost leak or something more serious? any help is good help thank you

 

[DragSourceTsi]

Could be a boost leak, the bounceing around make me think not.

How did your MBC cause a vacuum leak?

 

[1wickedGST]

It was a turbo XS standard MBC and under one of the rubber o-rings on the body there are two bleeder holes and when the car was running i could hear air leaking out from the MBC so i took it off and discovered the two holes, i reatached it and the leak only went away with the boost screw turned all the way down (now i see why they are so cheap )

 

[1wickedGST]

problem fixed it was a boost leak at the throttle body