I've done a step by step to have an idea what worked or didn't.

Started getting misfires under load. Read a bunch and decided it was COP, plugs, injectors or all the above.

Started with the COPs on the offending cylinders. Fixed! For two days

Replaced all 8 plugs (figured if I'm there, do them all), used dialectic grease replaced 3 more COPs for new codes. Fixed! For 3 days

Replaced injectors on the most recent 2 cylinders to flash codes. Fixed! For 1 day

All replacement items are actual OEM products. We've had this truck for only a few thousand miles of its life. It has be scratching my head. A lot!

The codes move around as to what cylinder but they are always the same thing. While it seems electrical, could it be something else?

What is the next place to check? Fuel pressure? Crap in the tank?

 

what did the plugs look like? And how many miles does the truck have?

 

I had one with an electrode that was wasted. I figured, based on reading that it was misfiring and cause the COP to go bad (first set of misfire codes). All the others looked good.

 

Have you tried changing the pistons yet? Might as well ehh.

 

then it could be from low compression due to a failing piston ring... i would check the compression

 

yeah, that's why i'm afraid to check!

 

but, why does the misfire move around?

 

May want to pull your crank & cam positioning sensors and clean them. Wouldn't cost you anything and you'll rule out trigger issues.

 

Charlie, that is what is next. The latest batch of codes basically says every cylinder is now misfiring! Thanks for the advise.

 

Pcm is a possibility. Also a bad B1S1 oxygen sensor. B1S1 is the front oxygen sensor on the passenger side