ok so got my ba xr6 t back after having it retuned by kpm to fix a boost problem, it made 288 at the wheels but now its having a problem with what they said either spark break down or maybe valve springs! what does everyone think? could it be that the plugs need to be gapped/replaced "were replaced 15,000 ago" or maybe the coils? or valves? car has a bigger front mount and new pipe work bigger injector and a growler induction kit bigger waste gate actuator and a tune running 13 psi