my 2012 failed the test, so they replaced the pistons and a bunch of other things at the same time, it made a world of difference.
I complained, bitched, moaned, screamed and begged for years before they finally conceded. Absolutely miserable experience. Never a GM product for me again, not because of the problem, but because of how they handled it.
2012 GMC Terrain – 81k (new pistons/rings, trans, master cylinder 2x, exhaust manifold, cat, fuse box, lower control arms, stabilizer end links, radiator and other various items)