About a week ago the CEL light came on and, because of whatever caused that, the computer disable the Remote Start. I couldn't get it in to the dealer for a few days and had to drive it that way. Here are some observations: First, the gas mileage seemed to improve by about a mile per gallon during this time. My driving habits and routine are pretty set and I usually buy gas from the same place so it would be hard to attribute the imrovement to anything else. Second, during that time I ran my best 0-60 time of 4.5 (previous best 4.7) seconds on the dash timer. I did this because the truck felt more powerful and that was my only way to confirm it. I wasn't that worried about doing it with the CEL on because that's usually not anything major in my experience. My final observation was that even though the "ECO" light never came on, you could still hear the MDS kicking in and out, so it was working. I do have only 1000 miles on the truck so I guess the improvements could be tied to vehicle break in but it seems a little weird that they happened at the same time as the CEL. Took it to the dealer yesterday and they said a cold start sensor had thrown an error, though they did not replace the sensor because they couldn't get it to repeat the code. But what they did do, and what I'm a little concerned about, is they changed the Flash PCM from P/N 68041671AD to 68041671AE. Call me paranoid, but I've heard many stories in the past about vehicles being debuted with too aggressive a tune and then all being de-tuned anytime they were brought in for warranty work. A pretty notorious one was Ford Diesel trucks a few years back. It seems OK, but I haven't had a chance for a 0-60 run yet. Sorry this got so long....just thought it might be interesting info to someone. Feel free to chime in with any thoughts.