I did a search on this topic and did not see any threads that described my problem. Occasionally when I take off from a stop, the engine will surge pretty badly two or three times then smooth out. Stomp on it and it runs fine. This morning as I pulled out of the neighborhood up a hill a couple hundred yards long it surged all the way up the hill. Brrrp....brrrp....brrrp....brrp. Stopped at the stop sign...proceded.....no surge. Makes no difference if the engine is warm or cold. Might go days before it does it then do it for three or four stop/go cycles then not happen again for a while.
2008 stock 6.7l w/62000 miles. 4x4 auto Mega.

Oh and it's not throwing any codes.

 

Mine will usually do this on startup after sitting for a while. Two or three hiccups and occasionally a puff of white smoke follows. Never gave any other trouble, so I never worried about it.

 

Problem solved. See related post in the latest overfull crankcase thread.