Changed out my fuel filter a few days ago at only 5,000 miles as a precaution and have not had the “chugging” issue occur since the filter change.
Like MBen said, sometimes it doesn’t happen for a week, so I am definitely “not out of the woods” yet.
Will let ya’ll know in the next few weeks if it occurs again.
I hope our results are different, but mine has done it since I changed my fuel filter which was about 6k miles ago.
I'm approaching 22k miles now, and the issue is much less frequent than it used to be. At this point, I want it fixed but the infrequency of it occurring has let me just live with it. As much as I want to force the issue onto a dealer for resolution, i simply can't afford the time for something that just doesn't happen regularly. Hopefully they really are working on the issue in the background and figure it out for all the affected owners. I guess it would be different if it was something I could easily reproduce and force to happen.
And, FWIW, I have also had it occur in Tow/Haul mode. I live in Colorado at 7500' elevation. The majority of my driving is between 5500'-8000' with the occasional mountain pass exceeding 10k'. I'm starting to wonder if this issue is environmentally related - I don't recall having the stumble occur when we drove (with enclosed trailer) to Green Bay, WI - which is obviously at a much lower elevation.
Just brainstorming here....
2020 GMC Sierra AT4 2500HD - Dark Sky Metallic
Sold - 2018 GMC Sierra Denali 2500HD - Dark Slate Metallic