I noticed the problem while still under warranty. I felt something strange (now know to be a miss fire) I was traveling out of town, and the problem was only momentary. I thought it was bad gas. It was only a short time later (conveniently enough, just after warranty expired) that the check engine light went on. The fix was to add a deflector pan in the oil pan, and replace the rocker cover with a newly designed one. Fully aware the the original was not working well. These two things are engine changes not just an average repair. GMC knows this problem exists, but refuses to pay because not enough people have complained about it. I have to wonder if the dummy lights are programmed to only inform of issues after the warranty mileage has been exceeded. I have purchased several Chevy vehicles in the past and have taken all of them to the same dealer for repairs. The dealer would not even consider helping out with this issue. THERE YOU HAVE IT. The consumer takes another one. (Lessons learned on the consumers' dime) I payed premium price for what I thought was a trusted brand combined with years of R&D behind them, only to find out they will learn from the consumers misfortunes and move on. It is this slap in the face that has lead me to move on to the competition.