Misfire in cyl 2 - Fuel Injectors?

Aloha All,

I've been having a problem with my 95 2RZFE for a couple months now. After the truck warms up it starts misfiring in cyl. 2 from idle-2000 RPMs. As soon as it gets above 2k RPMs it runs great again.

The weird things is that this only happens after it gets significantly warm. I can drive for an hour or so on open roads/highway and it's great. But if I drive for 10 minutes city style "stop and go" it acts up right away. And the longer I drive it after it starts acting up the worse it gets. Also, it only misfires in cyl 2.

Codes: 0420 (CAT), EGR insuficient flow, Misfire in cyl 2

I've replaced CAP, Rotor, Plugs, Wires, Fuel Filter, Both O2 sensors, Radiator.
I've also gutted the CAT, cleaned the MAF, and swapped Inj 1 + 2 (still getting cyl 2 code after swapping inj.)

The problem persists and is getting worse. My last hope is to replace the Fuel Injectors. Any advice, help, guidance would be greatly appreciated. Mahalo.