Is the 2003 Mazda Protege an interference engine?

Yes, the 2003 Mazda Protege is equipped with an interference engine. In an interference engine, the timing of the valves and pistons is such that if the timing belt or chain fails, the pistons can collide with the open valves, potentially causing significant engine damage. Therefore, it's essential to maintain the timing belt and replace it according to the manufacturer's recommended schedule to prevent failure.