help

[firebirdTA20]

so heres the problem. My 94 trans am is still runngin badly but i am getting closer to finding out what the problem is. When i first got the car it was running kind of rough so i decided that a tune up would probably help so i started with plugs. But the old plugs were gapped at .30 thousandths and they were supposed to be at .50 so i gapped all the new plugs at .50 thousandths and the car ran good for just a little bit then it all went down hill. so i replaced lots of different things that needed to be replaced anyways, like the EGR, MAP/MAT sensor, IAT sensor, Right side o2 sensor, declogged my cat converter since it got clogged up after doing the plugs, replaced my plug wires, coil, cap and rotor, and distributor,and i also got a different ECM, but none of those things fixed my problem i still had a misfire, and my car hesitates when you first hit the gas but then smoothes out, it also was backfiring. Then i was told that my distributor was probably defective because i made the mistake of getting my parts from autozone so i replaced it again since it had a warranty, but the problem was still there. So i started thinking that maybe the plugs were gapped at .30 thousandths for a reason so i took each plug out and regapped them down from .50 to .30 thousandths and most of my problem went away. it still hesitates and backfires a little but not near as much as it did with brand new parts,and everything set to factory specifications. So that is telling me that there is still something wrong but gapping the plugs down to .30 is basically telling me that at .50 the spark cant jump the gap as good as at .30 so something is making my spark weak, but it doesnt make sense because it has a brand new ignition system so i have no idea anymore. does anyone have an idea of what would make it do this, im running out of money and things to replace, im about to just give up. I know someone has to have and idea or have had the same problem as me so please help me out thank you.

[GETGONE]

Did you replace the fuel filter yet? I had one get clogged on my 00 Xtreme and it acted like it was the ignition. Replaced it and all was well. How did you unclog the cat? Hollow it out?

[firebirdTA20]

yes i did replace the fuel filter i forgot to mention that. as for the cat i just hollowed it out with a drill and welded it back up,