Abstract: A system and method for deterring catalytic converter theft are described. A variety of devices are described which can be installed as needed on the underside of a vehicle as part of a system to prevent easy access to the points where a catalytic converter is connected to the vehicle, thus deterring theft, or to prevent a catalytic converter from being removed from the vehicle after being disconnected from the exhaust system. The method comprises installing said devices to prevent this access. The devices may be installed separately or combined to protect multiple catalytic converters as needed and as dictated by the particular design of the exhaust system of a particular vehicle.