2002 sport trac Miss fire

Hey out there, just put new plugs and wires in the trac and has a miss. Pulled codes p0301 and p0316, changed wire and plug on number 1 cylinder and still have the miss. Did all the normal checking the plugs and wires, nothing. Please help.

Did you put in the new plugs and wires because of the misfire, or the misfire started after you installed the plugs and wires?

-Rod