Clarkie GT

noticed yesterday when i put my foot down, my car apears to miss fire a couple of times when coming on boost, it doesn't sound like a missfire, just holds back for a split second like its hunting for fuel or somthing. ive just serviced it, using ngk platinum plugs, changed oil etc. i dont know if it was doing it before cause it was overdue a timing belt change, so only just started using a bit of throttle.

has any 1 experienced this before? or is it a common problem?

oh.. and its a 1995 wrx with a ej20