I have read on other sites that this is a chronic problem on some Hyundais. When it first started, it prevented me from getting my car State inspected because it prevented the internal computer from sending an emissions reading. I spent a day and $350 at the dealership while a mechanic sat in my car and ran the engine at different speeds until he got the light to go out. Since then, it comes off and on intermittently. I have been told that on some cars this happens after a repair or an accident; the light goes on and then goes off after driven a few hundred miles at various speeds. With my car, there is no consistency. It comes on and then after a few days or weeks it goes off. I just ignore it now. I just wonder what if there really is something wrong with the engine and I ignore it, how will I know???