Hi all my 95 wrx wagon has started missfiring/hesitating when i floor it. It seems to do it more when ive been driving it steady for a bit then boot it if i carry on booting it, it seems to clear then run fine. I changed the plugs about 1000 miles ago and has also had a new fuel pump about 300 miles ago. The car has a cone filter and magnex exhaust and has boost turned up slightly to about 12 psi. Thanks in advance.