Rough idle and shifting, loss of power - 2008 Avalanche Hey all, Just traded in my 2011 Silverado for a 2008 Avalanche LT 4x4 w/68k miles. I have had it for less than a day and so far the problems I've had are: 1) Service stabilitrac 2) Service traction control 3) Tonight I was driving home from a friend's house when I felt it violently kick from first to second and then the check engine light came on and now the engine shakes and shudders at all times. My guess is some bad sensors for the first two issues and not sure about the third issue. Anyways, I purchased GM Protection Plan (Major Guard) so I'm going to bring the truck by the dealer and have them take care of it. I'll keep you guys posted on what the dealer said and my review on the GMPP. In the mean time could you guys throw out some ideas as to what you think it could be? Thanks!