I have 8900miles on the truck now, and today was the first time I noticed I was billowing smoke out the back while it was in regen.
I was idling at a stoplight for a couple minutes as it was in regen mode in front of a hill and it seemed ok, but I was spewing bluish smoke the whole way up the hill. It was hard to see what color through my sunglasses, but don't think it was steam from the way it dissipated. Once I made it over the hill it going no more than about 40mph and back down, it continued to regen for the next 20min on the freeway with no incident.
No stumbling or drivability issues that I noticed. It seemed to run just as raspy as usual when regening.
I think I've read some guys complain about the same, but never saw any conclusion other than replacing the CAC or EGR to fix steam(?). Someone mentioned the dealer said it was normal. I don't remember the manual mentioning anything about leaving clouds of smoke during regen.
Last oil change was about 3500miles ago. I've been using to the same Shell or Chevron
fuel stations. mpgs have been consistent. It's been pretty dry and 60F~70F outside. Humidity isn't an issue around here in SJ.