I had the same rattle. Was toldI have about 6k miles on mine and no issues. There is almost a rattle sound from cold start, seems to coincide with what we used to consider choke activation, while the RPM's are higher than warm idle. I think it's coming from the exhaust, maybe cold cats or something. It goes away pretty quickly, within a minute or so depending on temperature. I normally notice when using remote start while walking to the truck. I figure it's normal. As far as driving, it feels like butter...