funny you say that, on my way home from work last night i experimented a lil bit and noticed i could actually hear the exhaust being forced through the crack from under the hood. it wasnt like that before, the only time i ever notice the leak from the mani was idle. so i pulled the cat last night and put in a straight-through p.o.s. that ive had lying around forever, and that was it! ol' girl goes like a bat outta hell again! so, if you go through those symptoms, you know what it probably is. thanx guys