Quick update. I added the RP Max clean to a 1/4 tank early sunday morning, and then added a couple gallons of shell v-power to bring it up to a 1/2 tank (about 14 gallons total.) Since then I have been running it hard, then letting it sit, trying to clean out the injectors. Initial response: Truck ran VERY rough from the time I pulled out of the gas station until I reached my workplace (about 22 miles at highway speed.) I mean BAD. At one point I thought I may have had to siphen the tank and refill it, but I kept driving it, hoping that that meant it was working. After sitting for 12 hours, it ran a little better on the way home. And today, it has been idling much smoother and seems to be more responsive on the throttle. We will see what happens tommorow, I still have 1/4 tank left to burn!