Rough idle and no power,

[ZWILD1]

Last week put in new plugs. AC rapid fire #8's along with new fuel filter ,all GM parts. Yesterday changed original O2 sensors ,car has 103,000 miles again new GM parts. Disconnected battery so computer could relearn new data from O2 sensors. I drove car for 1.5 hours and stopped. Got in to go home and car started but fired almost like an after thought. I was stopped for about 3.5 hours. Idle was rough and there was a miss you could hear in the exhaust. This morning car starts ok runs smooth . Turn it off after 15 minutes and when I start it again rough idle is back. At about 78,000 I had a coil go bad which seems to remind me of how it ran with a bad coil. I replaced all four coils and plug wires then that was two years ago. All 8 are firing now but sounds like cracking or knocking under plenum when I pull some of the plug wires while it is running. So I pulled the plenum I don't have anyting to test wires or coils. Thinking of replacing coils and wires, I have new wires, If I could find out if a coil went south I would use one of the good originals I saved. Has anyone seen this sort of problem before. I will say I have felt like something has been going on for a few weeks. You can just tell by sound and feeling. Not as strong just alittle off.