99 Caravan 3.3 misfire multiple cylinders again after replace coil
 

I have 99 Caravan 3.3L engine. The check engine light came on a while ago; scan the code, it shows #3, #6 misfire. There was occasional ruff idle. I replaced the ignition coil (BWD from advanceauto); after installation, disconnect and ground the battery to clear the code, then the check engine light went off, and car ran smoothly.

Today (4 days after I replace the coil), the car ran ruff again when I pick up the speed, the check engine light flashes, then stayed on. From my trip meter, I drove 112 miles, and 4 hour 20 minutes. Scan code shows multiple events of #3, #6 misfire, multiple cylcinder misfire.

I can replace the Coil, but before doing that, I would like to get any suggestion on what else it may be.

Thanks,

Wiring from the PCM to the coil or the PCM itself. #3 and #6 are both fired by coil #1 in the coil pack. It's likely either the wire to coil #1 or the coil driver in the PCM is failing.