I have an 07 5.4 with four missfireing cylinders. There is barely any power delivery. Anyone else have similar problems?

 

Check your FPDM. Are all 4 misfires on the same bank? Pretty rare to have 4 occur at once - likely an issue with fuel delivery.

 

Another possibility if they're all on the same bank is the harness, or a clogged cat.

Did this happen al at once, or were there symptoms prior to misfires on multiple cylinders?

 

Its cylinders1 2 3 and 7. Yes it pretty much happened at once. Its under warranty still so its going back to the dealership tomorrow.

 

I'm not very mechanically savy, but since I'm learning how to change out spark plugs...

I've read that bad or improper installation of spark plugs can cause engine misfires. The repairs to those ain't cheap either.

 

will i have a 5.8 that is doing the same thing but mine is only 2 and 6 i have put new plugsand wires and cap and rotor its not the motor it hold at 160psi on all 8 and put a new idle air valve and mas air sensor and new coil but when she is cold it runs good when it warms up it miss's bad and starting to **** me off im going to pull the two inj's and move them to see if it changes any thing and i am not geting any codes to help me i do not know what the hell it is