Persistant problem driving me nuts!!

I have a 2005 tiburon and it started misfiring on cylinder 2 and 6 with random multiple misfire.
Took to a shop and they said MAF. Ok, easy enough. Bought the new one, installed, reset the ecu, car ran fine. about 2 months ago the car started acting sluggish, mainly trying to push higher speeds in 5th and 6th gear. CEL code came up saying cylinder 1 misfire. Since I was on the highway i just babied it til i could pull over but before I could the code went away and the car was running ok again. For the past couple weeks its been really intermittent misfiring. Off and on all day long. Went and bought new plugs. NGK Laser Iridium, new wires, and new coil. Got it all back together and still cylinder 1 misfire. Could it be the injector on cylinder 1?? I thought about switching it with cylinder 2 and testing it but that is alot of work to just test it. Anybody have any other thoughts since the ignition system is all new and so it the MAF?? Any thoughts would be great. Also checked for VAC leaks and everything checks fine there. Its a 2005 V6 with only 18,000 miles on it