That dreaded random misfire =(

I have a 96 Grand Voyager that had had sat for a year undriven or started due to being out of state. It ran like a champ when I parked it. Now I charged the battery and went for a drive on the freeway and my check engine light came on and started blinking. I had the code read it came back with 2 codes a P0306 and a P0300. I noticed that the cylinder 6 spark plug wire was arcing on the core support. So I replaced all the plug wires and spark plugs with Champion platinum spark plugs. I cleared the codes and took it on a test drive and the P0300 code came back. Is there anyway the old gas is causing the random misfire? or what else could it be?

Especially read "Random misfires that jump around ..." http://www.obd-codes.com/p0300

Gas? Probably not but try to get fresh gas in it as soon as possible just as a CYA.