3.0L Duramax
I have a 2021 Yukon Denali w/ Duramax 3.0. It also chug, chug, chugs at Key-Off. The exhaust becomes loud intermittently, usually after exiting the highway. It can be annoyingly loud when idling through a parking lot. It can go away; or last until I start it the next morning. Has anyone ever...