For about the last six months, my car idles roughly while at a stop -- the engine is very choppy. About a month ago while stopped at a light, the engine cut off. I was able to start it again immediately. Two days ago, the engine cut off again while stopped at a light. I was able to pull to the side of the road, and start the car up again after about 15 minutes. Yesterday while driving on the freeway the engine cut off. Once again, I was able to pull to the side of the road and start the car again after about 20 minutes, and drive home without issue. Any thoughts?