My 2014 LTZ developed what seems like a misfire when accelerating on the highway in the 2k - 3k RPM range. I took it into the local Chevy dealer, and they said it was a bad spark plug. They replaced the plug - but the problem was still there. They then replaced the ECM. The problem was still there. They have had the car for a week now - and still can't figure out what the problem is! I have a new Malibu as a courtesy loaner - but I miss my Cruze! A week with no resolution seems pretty lame (to me anyway), right?