Light comes on engine runs like poop. Sometimes runs great. When it is it runs like a scalded dog. Truck shutters then light comes on and loose power and just runs bad. If light comes on I can turn truck off let coast a couple seconds start it back up and will run good again. Could run for hours or days or just seconds. Very intermittent. VERY ANNOYING. Can anyone help. Changed filter and PCM (I think) Dad's truck.

Thanks