I have a 2012 Altima that I am having issues with and was hoping to get some help to resolve the problem. The car feels like there is a miss/rough idle/stumble but it only seems to happen when I start it after it has been sitting for awhile. So...It does it first thing in the morning and again when I am leaving work. After driving 3 or 4 blocks or so it smooths out and runs like a champ. I should mention that it only happens if I take off right after start up. If I let it run for awhile before I take off it seems fine. There is no CEL and I've had it scanned to see if there were any codes stored but there wasn't. I have replaced the plugs (NGK $20 a piece) and the coil pack boots. It's been going on for almost a year and it's driving me crazy. I would be happy if what ever it is would go out so I would know what to fix. Hoping someone can help me with this or at least point me in the right direction. Thanks in advance! Robert