My Graphite would act up on hard acceleration, but then go back to normal at idle or mild throttle. The car had 90,000 or so miles. 12 plugs and 12 plug wires fixed it.

In your case, i do not think it's a clear. But it has to be ignition or fuel delivery. Remember, not all "misfires" are ignition. I kinda suspect yours is fuel delivery, based on how the symptom "lasts after going back to normal throttle".
But I sure do not know for sure.