Sometimes it's the things you overlook...

Must have been running pretty bad missing 2 holes...

Cold tubes would have been a secondary indication.
My neighbor drove in with another car awhile back while I was out doing something on my car and I told him I didn't know a 86 Pontiac Grand Prix ever came with a V6.:D
2 plug wires were reversed and it smoothed right out.

Point is, I could hear 2 cylinders missing from across the street.