I have an 01 5.4 4x4 w/ 155k. I have had new injectors fuel pump and everything in the system cleaned or new in the last 7k. So I had put some Lucas fuel additive in. And soon after my truck started missing on all 4 cylinders on bank 2. I thought maybe it needed some clean gas so I filled up and tried to run some through it. And when it gets warmed up it's runs perfectly fine but only does so for maybe 5min. I have unplugged the cops on bank one while idling and each one would miss while unplugged. Not to be said for bank 2. I pulled the plugs on bank 2 and I can't tell if they are wet or not but they do smell of gas.
I was thinking maybe an electrical/sensor issue?

 

Flush the tank, change the filter, blow out the injector filters or have them sonic cleaned. Yea, don't use nothing Lucas with these. In fact use ONLY Techron. Sounds like you gummed things up. Confirm with a pressure test.