I have been lurking on this site for a while and wanted to see if there were any updates. Anyone who can help with my below questions would be awesome! 1. Anyone had luck getting transfer case/trans replaced CPO? Definitely starting to have trans issue and the first dealer said to make sure its not in 4WD all the time and to try and take Grade Braking off. It does ride better but still weird shifting. Thinking about taking it to my local guy and see what he diagnoses and then go back to GMC. 2. Anyone know of good shops in NJ for performance upgrades on 2016 Yukon Denali? I am looking at Exhaust and a tune. I have heard tuning can help with the shifting issues. Makes sense but not sure if anyone can attest to that? 3. When idling, it does seem to work pretty hard - is that normal for other peoples 6.2L? Plan on taking it to the GMC dealer but they take FOREVER around me and didnt address my trans complaint the first time I was there.