17's have had it happen too. Not sure whether there's any correlation between Mexico/US assy for the 17 model year.This sounds like an early run manufacturing issue. Later engines haven't been having this issue.
GM's TSB for piston replacement specifically calls out looking for leaks or conditions that may cause it to run lean. I haven't yet had an O2 sensor issue on my 16.5, but I could see that as doing it.Thats interesting because we do have people on here with 2016.5 with no issues and have close to 40000 miles. I am at 14000 and my car runs great. Just had the O2 replaced for the P015B code that seems to be popping up. Was the O2 sensor and this code causing this issue of running lean and burning up pistons?
12.5 or so.Do you have a copy of the TSB? Also how many miles do you have on your 2016.5? Mine runs great, it has had a little rough idle a few times but nothing big.