Dealer said they did something to the computer without being authorized by me. I took it in complaining of rough idle(missing) at idle after it's warm. They said it was to "re-learn" the computer. Now I get white smoke for just a bit on start up. & it stumbles badly for a bit as well. I watched the rpm's shoot up over 1200 right after it cranked over also. DOES NOT like starting in sub zero temps outside. Any advice would be much appreciated.

Thanx in advance!

 

I would be leaning towards a injector going out or leaking down over night