I had this code on my truck also. After doing a lot of digging around, mine turned out to be a wiring issue to the sensor. The insulation on the output wire from the sensor, had cracked and split, where the wires entered the wiring harness. Moisture was causing a very minimal short to ground. It seems to me these sensors are very sensitive to ground shorts. Took all the plastic covering off the harness and used brake cleaner to clean everything up. Taped it all back up and the truck has been running ever since!