Pontiac Repair: misfire under load, chevron techron fuel system, chevron techron fuel system cleaner

Question
I have a 95 firebird with the 3.4L and just had the battery tested today. i need to replace it even though i have only had it for a year and two months. now my car has been running fine until this morning, it was very cold, so cold that i had ice on my windshield when i left for college in the morning and my alternator was squeaking. after it warmed up to 180 about two miles down the road, it started to misfire a little when i would try to pass someone up (under load) but when i managed to make it to the school it was misfiring in every gear and barely noticeable in neautral. when i got out of class i turned it on and popped the hood, and listened to it. it sounds as if there is air escaping from somewhere every second or so. and even though i had just turned it on, it would shake like a misfire every time i would rev it a little. i also recently replaced the plugs and wires, never the coil packs, but later i checked to see if the coil packs where sending a spark and all three were emitting a spark. i haven't pulled off the wires from the plugs yet, didn't have time. but plan on it. other than bad wires, any ideas? i've had that "air leak" for a while and thought it may be my exhaust manifold on the driver side, but i pulled it off, and replaced the gasket. to no change, but i do know i needed to replace it, since it was basically disintegrated. i hope its just some bad wires that may of had gotten burned up and i haven't seen them yet. any help would be greatly appreciated.

Answer
Hi there:

It's possable. especially if you have a cheap set of wires. Use only ac delco wires or a good set from either NAPA or Carquest. use a "spark cheker" at the plug end of each wire and see if yu indeed have sprak on each wire. That engine was noted for injector issues plugging up. Try a bottle of Chevron Techron fuel system cleaner and see if that helps too. A lean (dirty) injetor will act like a cylinder that is lacking soark as well. Good luck :)