fitguy

I've have a 98 Stang-3.8 throwing a PO302 (misfire cylinder 2). For over a year, it's had a random rough idle. ACtually, it's really a violent shake. However, driving down the road or getting on it, there is NO power loss at all or skip. At times, I can feel a little hiccuping if I hold the rpms about 2,500 rpms... Not too bad, though. Again, this happens randomly. Other times, the car idles smooth.
WHat I've done:
changed spark plugs/wires
cleaned AIC
Cleaned MAF
Checked EGR
Checked Canister purge valve
checked for vacuum leakes
changed fuel filter
ran sea foam through the tank, twice
Changed both upstream 02 sensors

I have read where this could be several other things. I think it could possibly be a bad injector. what do you think?
Any wise suggestions is GREATLY appreciated.