I think my car has air leak or is overboosting as between 1k and 3k revs it jerks slightly.. And the boost has cut out and started spooling up again when putting foot down in 5th gear to speed up.

I have a 96 wrx sti with straight through 2.5" exhaust (with resonators) and mines ecu (info from previous owner need to check this)..

How can this problem be sorted?

 

bump ..anyone? *thread title is meant to say 'air leak or is it over boosting?'*