Well finished my motor install yesterday and now it runs like crap. when trying to go WOT or even half throttle from about 2000rpm and up it backfires like its going way lean and tries to kill itself. I have searched for similar problems for a while now and i just can't figure this one out. i have checked fuel pressure ( 44psi ), my EGR crap, timing, spark....i'm just at a loss on this one. Also it seem to do it more while under load...not so much while its just reving