Alright my 06 wrx is stock except for cobb stage 1,cobb short ram and STI cat back.When I acclerate the car usu. boosts up to almost 15 p.s.i. and then drops back severely(to 5-8 psi or so) and then goes right back to normal boost until the next time i give it near full or full throttle.No check engine light or other issuers that I can find.It started doing it in the last week or so.And not all of the time either.I thought it might be overboosting and then the boost-cut was kicking in but I am not sure how that would feel/appear.