Yeah to second what the other poster said, it can indeed mean a lot of different things. Sometimes it is as simple as an emissions error but sometimes, especial

Yeah to second what the other poster said, it can indeed mean a lot of different things. Sometimes it is as simple as an emissions error but sometimes, especially if you ever see it flashing, that means there's something bad wrong going on with the engine itself. It could be anything from a knock or misfire in the engine to sensor failure. It's always wise to get it checked (a lot of auto parts stores do it for free) or just buy a cheap but good obd-2 tool and that will tell you the code and you can go Google and research from there.