Chas87F150, by DFR do you mean that 6 port valve on the frame rail under the driver side door? If so it made mine cut out just like Kart18 is doing when i was driving down the road. this was about a year ago. Replacing my fuel filter and 6 port valve fixed mine. It would run fine for a while then all of a sudden act like the key was being turned on and off or bucking like a plow mule. It would flat out die sometimes but would start back up after setting a few minutes. Replacing the computer would have just fixed the rich signal he was getting from the negative 0.5 bias.