I pulled the ISX out of my 2014 Pete and replaced it with an older Cat (different ECM obviously) my new engine has a new ECM. My odometer never changed. My hour meter reset to 0.00
I had an ecm change on a 2013 some years back. Miles went to zero. My guess is the miles are legit. It’s a 2016 right? Probably went into service in 2015 and ran regularly for 4 yrs then sat a lot this last year. Cummins sells a 2nd owner warranty called Encore XT1. It’s about $4500 for two years 200k miles. It paid for 2 full overhauls for me. Good program.
Personally, I'd avoid that aftermarket warranty. Just use that search bar on this site and you'll find hundreds of posts about how its a sham. OEM warranty is the only warranty worth purchasing IMO.
Yes, it’s because that’s what pads THEIR pockets. Google Encore XT1 warranty and locate it on Cummins site. It’s an actual REAL warranty.