if the light is blinking it is usually a misfire. You can confirm this by hooking up a code reader. With a misfire it could be bad Spark Plugs, Wires, Dirty fuel rail and injectors. If you have not had a complete tune up done you might want to do that, plus it will help get you better gas milage. You should change the Plugs, Wires, and put a gas additive in. You could have a coil also going bad.