This is my 1991 z28 5.7 Camaro, having trouble with diagnosing the problem.
I was at a stop light on the way to school and heard it get a little choppy like it was running on 7 cylinders i pulled into the gas station and noticed it was starting to get worse to the point it would stall if i put it into gear, so i got it towed home. I found a couple vacuum leaks and replaced the idle control valve and even relearned it and checked the codes and no check engine light. it still runs like ****, curious on if you guys have any suggestions on what to do next

 

Video posted is it running on 4ish cylinders

 

Might want to post this in the TPI section.... probably doesn't have anything to do with the ERPOM.

That said, if it's truly a misfire that developed in a single cylinder... some things I'd check...

1.) Not saying yours is like this, but I've seen a number of cars over the years with very, I'll say, less than neat spark plug wire routing, where wires are near exhaust headers and stuff. f your spark plug wires are in a similar situation maybe one hit a header tube and burned through.

2.) One of your spark plugs fouled

3.) Some problem with the valvetrain... broken valve spring, bent pushrod, one of the rockers loosened up and/or broke, etc. You'd have to pull off your rocker covers and inspect it.

4) Faulty injector

You can also potentially identify the misfiring cylinder by going around the engine and disconnecting one injector at a time (or one spark plug wire at a time). If you come to a cylinder where the engine doesn't react, then that's probably the bad cylinder. But be careful pulling spark plug wires so you don't get zapped (probably wear thick rubber gloves).

Based on the fact that you're saying it got worse over time, I'd expect the problem to be on the driver side of the car. If one of the above (or something else) happened, the O2 sensor would pick up the effects of it in the exhaust gases and the ECM would start adjusting the fuel to compensate. So it could be that the fueling was either getting richer or leaner to the point where the fueling to the entire engine either got extremely lean or rich, based on the one cylinder's malfunction.

If the problem was on the passenger side, the O2 sensor wouldn't detect it and the ECM wouldn't see it. So it would run rough due to the misfire, but it wouldn't necessarily get worse over time.

It's one of the weaknesses of these OBD 1 systems.... one cylinder malfunctions on the O2 side (driver side) and it takes the whole engine down with it. Multiple cylinders all over the engine running rough or misfiring due to being overly rich or lean, because the root cause was originally one misfiring cylinder on the driver side of the engine.

 

I had an issue similar. Plug wire #8 unplugged itself.