We have replaced spark plugs and coil pack 3x and after about a week, it goes back to same thing.
Engine is idling rough and check engine light on Codes:P0351,P0350,P0301,P0174
on 2000 Ford Explorer
I'll give you the flat rate tech's most probable cause checklist, check the wires at the connector at the coil specifically the wire that controls #1 cyl firing,you'll need a wire diagram for this. make sure the wire is not broken,it'll feel like stretch armstrong's finger if the wire is broken at the connector.if that feels normal, connect a test light with the clip on the batt. positive terminal and probe the pin in the coil connector while someone cranks it,should flash.if no flash then ohm the wire between the coil and the pcm for open circuits,if no flash and good circuit then you have a faulty pcm driver. if the circuit is open,just backtrack until you find it.good luck