I have a 2005 2500HD, all stock (as far as the engine is concerned) and every now and then, as it shifts to it's last gear, around 60 mph, it will give a little cough. Usually under moderate acceleration, i.e. highway on-ramp, accelerating to merge with traffic.

Doesn't do it every time, and no codes, therefore the dealer (have taken it in twice) says CND.

I'm just over 11K, and it has done this at about 8 times. Any ideas?

Is it hanging up at 2K RPM? With 11K miles on it you might want to change the fuel filter. I had similar issues at 10K and the FF fixed it.

Do the fuel filter if you haven't yet...it's probably time. And search around on the site for turbo "bark". My truck "barked" a bit when it was new at medium throttle shifts. Usually if I was just lifting a little and the truck was shifting at the time. Makes a "woof-woof" sound with air that is being pushed out of the intake.

MDX - you hit it pretty much on the head with your description. I was thinking along those lines, but wanted some feedback from here.

I did change the FF at about 10,500K, 35% life inidicating on the computer, but it was doing it well before (started at only a couple K). I'm pretty sure it has done it once since.

Operator error? I could very well be letting up on the gas just a touch at that point. ):h

Unplug the EGR connector and it will stop doing it. Search on it, it's a 30 second job. No check eng light but you may get codes in the background.

I do have EGR unplugged and it doesn't happen to my truck now...it really only did it for the first 2k miles or so.