Thanks for all the replies. I have checked plugs and all seem good. even replaced the wires because i ripped an end off. no change.
when I pull the fuel pressure regulator vac line, the pressure goes up but stumble is still there. I don't think it's starving since bank 2 is super rich. exhaust smells confirm rich state. Tank, strainer, pick up and fuel pump are all brand new.
tried swapping all injector left to right. still no change.
lastly, this only happens for first 45 to 90 seconds. after then, rich condition goes away on scan tool and truck runs fine the rest of the key cycle.
no check engine lights either, no codes in computer. staring to think it's an O2 heater issue on the right side. figure the heater should run for the same amount of time im having the issue. going to try this soon:
https://www.motor.com/magazine-summa...cuit-failures/