Chevrolet Forum - Chevy Enthusiasts Forums - '92 Z24 cavy intermittent missing/running rough

So off and on my car misses really bad. Spark plugs are only a couple months old, pulled and check them yesterday, they're fine. Pulled the coil packs and cleaned them up real good, still missing, bought new spark plug wires, still missing.

before i bought the wires, I would pull one wire at a time and stuck another spark plug in it and started the car to double check that they were all getting spark, which they are, but when I finished it ran normal but with a couple misses here and there. So I figured the wires were shot and that's why I bought a new set.

I also gave it an oil change and put Lucas Oil Stabilizer in it, because it was long over due for a change anyway. The car has just about 210,000 miles on it and this is the first hiccup I've ran into since I bought the car.

ran my OBD I for GM on it and it only pulled code 12, which from what I understand is just a default code to say the diagnostic system is working correctly.

A friend told me possibly an O2 sensor could cause it to run like that, but I don't want to keep buying parts that wont fix the problem. Anyone know whats going on with this thing?