I have a 2008 Toyota Corolla. My check engine light came on for about a week, but is now off again. I noticed that when I am stopped at a traffic light or even when I'm in park my car starts shaking and feels like it's jerking forward. It doesn't happen all of the time, but has been happening more frequently lately. The rpm meter also increases and decreases slightly when this happens. I haven't had any other issues with my car. Any help is appreciated.