Chrysler Repair: 99 V-6: cylinder #2 misfire, chrysler 300 m, spark coil

Question
My 99 Chrysler 300 m has been shaking when stopped at a light and in gear but not when in park.  Occasionally it will also shake when driving as if hesitating to move.  The check engine light just came on. I had it checked at Autozone and was told that it was a cylinder 2 misfire.  I had my brother change the sparkplugs this weekend and it still continues to do the same thing.  I just spent several hundred dollars repairing the car 3 weeks ago so if anyone has any suggestions for things my brother might be able to do before I do it again,I'd appreciate it.

Thanks!

Answer
Hi Kendra,
Other than a spark plug, the other possibilities are that the individual spark coil on that plug (there is separate coil for each spark plug) is faulty, the injector for that cylinder is faulty, the low voltage wires to the coil have been damaged (inspect those), there could be a problem with the valves for that cylinder (do a compression test of the cylinder), or an intake manifold leak in the vicinity of the cylinder.
You could try switching the spark coil to a different cylinder and then drive it and then have the codes read again to see if the problem is now identified at the cylinder to which you switched the coil, which would prove the problem is the coil that originally was on cylinder #2. You could check the resistance of the injector for that cylinder and compare it to that of another injector. You could try some injector cleaner in the fuel. You could try idling the engine in gear, and then spray some very short bursts of starter fluid at the edge of the intake manifold in the vicinity of that cylinder to see if the idle speed jumps up or down when you do that. But use very little as it is highly flammable.
Those are the approaches to find the cause of the problem short of analysis at a shop.
Roland