Saturday my check engine light came on. Wednesday, several trips and about 460 miles later, it went off. Should it have gone off by itself, or stayed on till being reset? Is it a good sign that it went off, maybe just a loose gas cap? I'm getting it checked Friday, but am a little worried since it came on before and was the cat. Cat wasn't replaced, but Honda said if the light came on again for the cat, it would need replacing.