Hi, if your engine light its blinking on the dash while you are cruising and the car it's hesitating, it means that you have 1 or more misfiring cylinders. That may be for several reasons: check your sparks, sparks plugs or ignition coil.[br]
Then if is all good check you fuel pump and filter, and be sure to have the correct pressure on the injectors and all working.[br]
In any case it's very useful an OBD Scanner, because it could tell you exactly which cylinder is failing so you can focus in that one.[br]
That's the easy and less expensive thing. if it's all good, it may be a head gasket or worst, timing belt or an endless list of possibilities.