i find that when i sit in a traffic jam for a while, my engine management light (MIL) comes on and stays on. itgoes off at random times, sometimes next time i fill up on diesel , or when i start up or just goes off when driving. i don't really notice much difference in performance. just wondering what it could be. i used to think it was just one of the lamba/o2 sensors getting too hot as sitting there idling and not letting the gasses escape properly so throwing up an error code. but im not sure. any ideas???