It could be a CSS, have you checked for codes? It is a fairly inexpensive part so you may want to try it.

 

Check for codes. Mine would stumble driving down the road then pick right back up. It was the crank sensor. Crank sensor is behind the starter. Pretty easy to change. Cam sensor is behind hte VP and a pain in the as* to change. Dont ask me how i know haha

 

Okay I think I got it set to public. See if the video works for you cats now.

 

That video is helpful cause that isn't what my truck does I would say that my rpms are just fluttering not all the time just sometimes

 

My programmer said my crank sensor is out, is on the front of engine on drivers side on a 05 cummins?

 

Did you ever find a solution to this? Mine is doing the same thing. It also has a very slight flutter when I'm cruising around 1750-2000rpms and when I'm stopped with my foot on the brake. I'm scared it's my VP

 

Just thought I'd update this old thread for future readers. I have 2011 ram and it had similar problems as what was asked. It would stumble or surge in the morning at 70 degrees like the heater grid was on. And then again between 1500 and 2000 rpms not codes and everything I can monitor through my cts2 seemed fine I have full delete or dpf and egr with 5 postion switch with efi. It was the cam sensor as well and I cant say for all 6.7 but i know 2010 up does have a crank sensor and it on the bottom front of the motor with a tone ring behind the balancer and it is the same part as the cam sensor. And one last thing if you do the cam sensor take tire and inner fender off and place a jack stand behind the radius arm and drop the hub to the ground makes it alot easy. Good luck to future readers with this problem.