Cylinder No.7 Misfire

I have a 1997 Dakota and the check engine light is on. I replaced all plugs, wires, rotor and distributor cap, and still having the code read back, "cylinder no.7 is misfiring". So I replaced no.7 spark plug again, thinking maybe it was a faulty spark plug. Same problem. The truck seems to run fine, but it kind of idles a bit rough, a slight shake to the engine. The only other think I can think of is a bad fuel injector. Any thoughts or replies would be greatly appreciated. Thanks in advance.
Dan

Spark plug wire routing is one thing.

Clogging injector might be another.

Best of luck.

dump some real good fuel injector cleaner/ fuel system treatment in it..sounds like a dirty injector