Up to 2020 they only had 4 of the DOD or AFM type lifters. So mathematically your odds were lower to have an issue. I had a 2015 and a 2017 Yukon with no issues. But many people had no issues...because there were less issues. Since 2021 the new design has more of these lifters. More issues. It has been said it was a defective Quality control issue from vendor, and a bad design?? We mere mortals have yet to get a conclusive answer to plan around or upgrade out of the issue. Some have had this issue twice?? If I were buying a used one today I would buy a 2020 and immediately swap to regular lifters and tune it out. I dont believe many tuners invested in cracking the computer on the 2021 on up so thats not possible. Many do this with the LS version when a lifter went bad. This truck is very expensive and a bit more complicated....making this so unacceptable. Fuel mileage and this issue have made the 3.0 diesel popular.