Random misfire, persistent problems

Hi all. Totally new to the forums so thanks for having me. I should mention first that I am by no means even a hobbyist when it comes to fixing cars so I apologize in advance for my lack of knowledge if I get confused about something someone mentions. Here is the history of my Firebird's problems.

Two years ago I had the dreaded oil and coolant mixing problem that these cars are known to have. Took it in to the dealer, they replaced the manifold gaskets, and to date they have not been mixing any more and that particular issue has been fine.

A year ago, flashing ses light, rough idle, hesitation, stumbling, misfired badly. Code was a cylinder 3 misfire. Replaced fuel filter - same problem, new plugs - same problem, new wires - same problem, then I replaced the coil packs - problem solved. It ran fine immediately after replacing the coil packs and didn't have another problem till a week ago. Same exact symptoms as before except this time it is a P0300 random misfire code and I am smelling fuel right after starting it which didn't happen before.

I removed the coil packs, was going to check them then realized I loaned out my ohmmeter so I put them back (without screwing them in) just so I wouldn't get any wires mixed up. For the heck of it I decided to start her up with the coil packs set in but unscrewed and the code went away and it drove up and down the road fine again. I hand tightened the coil packs and it was running great. Then today it started idling very rough. I decided to clean the MAF sensor and replace the K&N filter with a regular one cause I heard they're not good for our cars and could cause a rough idle. After cleaning the MAF and replacing the air filter, the misfire problems came back. Talk about frustrating. I'm wishing I just left it alone when it was running fine but I knew the MAF had never been cleaned. Any and all help is greatly appreciated.

I figured I'd try what "fixed" it last time so I took off the wires from the front two coil packs, removed the coil packs, waited a little bit, and very very lightly hand screwed them back in, problem gone again. This is so weird. What in the world would cause it to act like this? I'm not touching those screws again unless it starts acting up again. But I'm concerned that if they are too loose that that in and of itself could be problematic. The coil packs are very loosely tightened but I checked to make sure they don't move up and they don't but they do wobble a tiny bit. I hate to leave them like that but if it makes the car run well again then I kind of have to unless I find out exactly what the issue is. Any ideas?

I know this is an old post but I'll go ahead and give my take.. Just incase someone else is having 3800-II trouble with it's coils.. Our coils are mounted over the right bank valve cover. The center coil is centered under the cowl and the wheather strip is over top of the plastic cowl cover. I discovered while doing some top end work recently that water can easily get under the wheather stripe and leaks right on top of the center coil then runs down and around the other two coils. I believe this is what caused me to have problems and eventually lead to my center coils death.. When I pulled them apart for some detail work I dicovered also that the water had caused the connection pins the become heavily corroded and covered with copper green patina.. As well as all the mounting bolts to become heavily rusted. One of the mounting holes for the coil has an imbeded ground, corrosion there could also cause a random misfire imho..