Thanks for your comments. I assure you, I am not a two-footed driver and floor mats did not cause the problem. The week before, a sensor in one of the front ABS brakes went out. We did not replace the sensor, because they couldn't tell if that was the sole problem, or if some relay would also need to be replaced. On the way home, the EPC warning light came on. When I took it back the next day, they couldn't replicate the problem. Just before the sudden acceleration last week, the EPC light came on again. The dealership has witnessed the sudden acceleration every time they have started it up since last Wednesday. They found some moisture causing a short to some wires that are contained in a sealed box in the engine, but they do not yet know whether replacing that (different) relay will solve the problem. I have 188,000 miles on the truck and would love to keep it going, but it might be time... In the meantime, I have a loaner.