As to that persistent #2 misfire . . .
Yes, it certainly could be a problem with the fuel injection system
If you’ve still got that Tech2 scanner you mentioned, you could easily determine that, using the injector balance function, in conjunction with a fuel pressure gauge hooked up to the test port
That said, a high level aftermarket scan tool, such as a Snap on solus, for example, will also be able to perform this function test
As you know, swapping injectors, for the purposes of confirming a stuck injector, is pretty much impossible, due to the nature of the fuel injection system
One of the poppet nozzles could certainly be partially or completely plugged, as this truck is 20 years old
The good news is that fuel injector cleaner will sometimes clear them up. If you determine that #2 poppet is indeed clogged, I recommend you run the engine on fuel cleaner hooked up to the test port. If’s more effective than dumping a can of junk in the gas tank. The stuff you hook up to the rail is much more potent, anyways
But before you do that, I’d perform a compression test on #2 cylinder, just to rule out a mechanical problem
And if you determine a poppet is clogged, and you are unable to clear it up, the standard procedure is to remove the plenum, and replace the fuel injection assembly with an updated part, which replaces the poppets with mini efi injectors. The cost is actually not that bad, under $300 if you shop around.