Got a P Code that indicates a misfire in cylinder three. I have a 2009 Nitro with 78k miles. No engine trouble to this point. I have read the list of possible sources for the PCode, but anyone here had the same issue? Of the potential origins of the alarm, what is the most likely? I am not looking for an online diagnosis, so hold your criticim long enough to actually read this post. What, of the possibilities, is the most common?