Hi hoping some one can give me some more info then i already read from other similar post.So yes that means i used the search bar first.2002 F150 4.6 2x2 150k only 15k on the Motorcraft plugs.Started missing on the Fwy @ about 60mph.Put the obd2 on it and said P0353 i did the motor swap 15k miles ago and everything was cleaned EGR ect and all new gaskets and have not had a single thing wrong ran like a champ.....changed the plugs again Motorcraft and new coil made sure the harness was not next to the AC accumulator thing......reset the code went around the block drove for a bit checked the scanner again and its back.....it neve tripped the cel even the first time....

 

Have you looked up the definition of the 356 code?
It would tell you 'coil primary side of circuit' for cylinder 6.
Is the coil plug firmly locked in place?
If yes, is the coil primary open by ohm meter test?
If no is the harness going back to the computer open at some point?
If no, the computer driver likely is faulty. If yes the computer has to be replaced and reflashed to take care of PATS and the keys.
Good luck.