Lumina Misfiring After Intake Manifold Gasket Change

Hey everyone!
So I've successfully changed my intake manifold gaskets and all seemed to be going well, but now the engine has started misfiring. I first started with all the vacuum hoses and they're all connected with no physical issues. Then I tried the spark plugs and all of them are fine. Next I checked the coil packs and two of the three packs were not firing off well enough. So I swapped them out, and now the misfiring is worse than before. Could it be a sensor maybe? I'm stumped at this point... any help would be REALLY appreciated.

Make sure the firing odrer is correct, if so try and pinpoint the dead cylinder/s by shorting out one wire at a time till there is no change then that is the suspect cylinder/s.

I had a misfire once and I could not determine which cylinder it was for sure. I put a new set of plugs in it and ran it 10 miles. Pulled the plugs out and it was easy to see which cylinder was not firing. The misfire was black and all the others were nice and white.
You could also take exhaust manifold temps with an infrared temperature gun. Coldest temp would be the misfire. I prefer the new plugs.

Well, the misfire turned out to be the ignition coil module. Got it fixed, and finally started, but now it's running a little rough until I get up to speed which it's then unnoticeable. Hopefully I can solve the problem with new spark plug wires.

What yr. & engine?