Recently, I've noticed that when I just start the car or when it's accelerating, the engine stutters. Two days ago, when I was driving on the freeway, the "Service Engine Soon" light blinked for a few times and went off right after by itself. I took the car to a local garage and was told that a diagnosis could not be performed unless the "Service Engine Soon" light was still on. What might the problem be? What should I do now? Is there a way to pinpoint exactly what the problem is? Thanks!