2017 F150 3.5 Eco Boost
Engine light came on a few days ago and stayed lit, went on the highway yesterday afternoon and while passing a vehicle the truck started to buck and the light started flashing and it began shaking very bad and all power loss. I read the code and it was a misfire cylinder #5 so I assumed it was a bad coil. I swapped coil #5 with #4 and wiped the DTC and after test driving several times I have no problems with the truck and no more engine codes just the yellow warning light on the reader and the C - O - EV indicators blinking on the reader.
Any ideas?

 

Very likely has absolutely nothing to do with the coil and your spark plug is fouled/worn enough that under heavier load it begins failing. 3.5 turbo is extremely hard on plugs. Put it in sport mode and hoon it a bit. I bet it'll put itself back into limp mode.

 

Makes sense, I’ve tried it several times in sport mode and still no code.. Truck is nearing 100,000 kms so I’m thinking maybe it’s time for a new set of plugs like you said.