truck sounds like its running on only 4 cylinders

the truck starts fine idles fine an starts off driving fine, but once i decelerate let my foot off the pedal the check engine light comes on and the truck sounds like its only running on 4 cylinders, this also happens if i rev it to about 2000 after i start it in park, if i rev it to 3000 or above light comes on truck sounds like 4 cylinders and then shuts off. i replaced the CPS, wasnt that. scanner said its my tps and cps even though i replaced the cps, tps i cant seem to find a direct replacement because ford stopped making this product. i havent found a similar post on any forum on anyones truck sounding like mine is, everyone else with a tps problem seems to have a different description of what happened to their truck when their tps went, anybody have any suggestions? similar problems? ialso read about the IVS....but appRently. o one makes that anymore either???? all help is appreciated

Is it losing a complete bank of cylinders? Could be the Valve cover gasket wiring coming lose

Uvch would be my guess also they are prone to intermittent cylinder loss there are several threads exposing the process of ohming them out for diag or if you have a capable scan tool a buzz test would yield similar results

unplugged all 4 harnesses multiple times plugged em back in wiggled em around, nothing, they looked fine when i had the valve cover off a few weeks ago

Did you do it while running? Because if you unplug it while running and nothing changes on that bank then it is your uvch but if you unplug it and your engine dies or runs rougher then the bank you unplugged is good.

If the IDM senses a problem on on bank of injectors it may shut down that whole bank. It may be the under valve cover harness on the side that is dead.

but if it is the harness wouldnt the scanner pick that up?

If the IDM has the whole bank shut down the the scanner may point you towards the IDM instead of the harness or injectors.

Doesn't point me to the idm either though

Not necessarily because the pcm's in our trucks aren't programmed to detect every electronic thing and sometimes it will get confused the best way to diagnose it is to start your truck and hell even just remove the valve cover and pull the electrical connection to each injector and the good one's you will notice a difference in the way your truck runs the bad ones there won't be any difference at all

I worked on a truck with a 4 cylinder bank failure and it had no CEL. I didn't pull codes though. That was the first truck i ever heard about with a full bank bad IDM failure.