Getting a code PO302 Cylinder Two Misfire so replaced the spark plug wire to cylinder two and still showing the code. What else should I try?

If I took this in to a dealership would this be covered under the power train warranty? We have 66k miles on it.

 

OBD-II Trouble Code: P0302 Cylinder 2 Two Misfire Detected

Spark plug would be my second move if I had no test equipment. Can you feel it miss? No idea on the warranty.

 

What kind of plug should I get? You can feel it missing about 30mph or so. Other then that it runs great.

 

Hi, has this engine got separate Coil Packs for each Plug.