I have an 02 Ranger with 86,000 on it. Check engine light went on. Code said misfire in #3. Changed all plugs and wires, problem got about 85% better. Still idles rough. Checked for spark and compression in #3 (as light went back on and same code). Both good. Ran Seafoam through fuel system. seemed better for a bit. Light back on and rough Idle again. replaced #3 injector, seemed better for a bit. 2 days later light back on and rough idle back.
Coil Pack next?????? there is a spark in #3 but same code.
Any help would be greatly appreciated. Thanks in advance.

 

Yes I would suspect the coil pack next.

 

Thanks, I guess my question now is, why am I getting spark but still showing misfire? I also don't get why at low rpm it's running rough but is smooth at higher rpms?

Thanks in advance,