i have a 2017 f150 stx with a 2.7 around 63000 miles truck started missing on and off. took it by a mechanic friend and put it on computer said coil packs 1-4 missing. changed all 6 coil packs and still did the same thing.about a week later was close to his shop when it really started missing. put it back on computer showed nothing but crankshaft speed was all over the place. changed crankshaft position sensor truck still misses of and on.checked all wires from coil packs nothing wrong.different mechanic said ecm probable cause. changed ecm still misses at times.sometimes check engine light comes on when it acts up but most times not. ready to give up. any suggestions

 

When was the spark plugs changed? Or have they been changed at all?

 

I am not trying to insult you, but this is what happens when only codes are chased and no Live data is looked for other clues, by a knowledgeable mechanic.
This is why you come asking.
Missing or low fuel pressure, fuel injectors, missing coils, missing plugs, Harness and connectors, moisture in the fuel, fuel tables out of normal spec, air leaks etc. are all part of the show.
Good luck.