Aaron, have you done a compression check on Cyl 2? It could be a remote possiblility that after it warms up, it is leaking passed one of the valves. Even if you have changed the plug wires, could also be one of those. My 95 Stro had a new set of AC Delco wires on it, started missing about 6 months after install....looked like a flashing Christmas tree under there in the dark. My first thought was coil, but then you would be having misfires over all cyls. I wuold still be leaning towards a fuel issue or compression issue in that cyl.
Have you talked to James from ASV yet? He's the expert.
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'99 Tahoe, 3" BL, 285/75/16's , MT II's.
'05 Liberty Sport, -wifey's
'98 Poncho Fireturd, 3.8L, .....the purple pig!