Start with the most recent...was the melted wire the original diagnosis for the mis-fire?
Melted wire, new replacement=rong firing order.
....is the SES light on? Rough at idle?
All the scan tool will tell is that you have a P0300 misfire code. (if in fact it is a MF)
Idle drop test....pull one wire at a time from the cap @ idle, note changes.
Loosen wires before starting.
...check dist cap for carbon tracks, replace cap & rotor if needed.
"Sticks & stones can break your bones...and hail will dent your Airstream"
So when is this..."old enough to know better" supposed to kick in?