So in May of 2011, my check engine light comes on and i bring it into dodge. They find out that there is a misfire on cylinder #4. No biggy, they replaced spark plug and all was fine. Then just today about a year and half later check engine light comes on. Went to the local part store and same damn thing misfire on cylinder 4. Just wondering if you guys think there is an underlying problem that keeps causing this or is it just crappy spark plugs? Any info is much appreciated!

 

Misfire would generally be the coil pack not the plugs. Swap the #4 coil pack to another cylinder and see if the problem follows the coil.