Yup, it's unlikely to be the pcm. Unplug the maf sensor and see what happens. Its the black box on top of the throttle body, has a three pin plug. Also check for obvious wire failure as I had that happen on my 98 GP. When you first start it, it will run rough, maybe even die and your SES light should come on. But after about 15 seconds it will realize the maf is unplugged and will run using the map sensor instead. If your problem goes away then that's your problem