Misfire Cyl 4

I had a misfire code for a while. At first it was random, then it was cylinder two after I did a plug, wire and coil change. Ended up the end wasn't on the plug tight enough. Pulled it off, applied more dielectric grease, reinstalled it, no more misfire codes. I also have been running Berryman's B-12 injector cleaner in the tank for quite awhile. It has Acetone, MEK and Methanol in it. Best injector cleaner there is. You might try some just for s and giggles. These vehicles are old and injectors do get plugged up. Especially if they've sat for any prolonged period of time.

Try getting the fuel filter changed as well.