Most modern combustion engines (gasoline and diesel) incorporate a catalytic converter in compliance with local, state and federal emission standards. When recycling a catalytic converter that is attached to your vehicle, remove the catalytic converter from the car and cut/trim the muffler pipe and any other exhaust components attached to the unit. If you look inside the unit and can see through to the other side, you most likely have an empty catalytic converter (or are looking into the muffler or resonator).
If you look inside the unit and see ceramic material with a honeycomb pattern (and the material is anywhere from pale white to gray or even brown), you have a catalytic converter. Units will be graded according to the amount of ceramic honeycomb inside. Some units may only contain half of the original material (whether from breaking and falling out or from burning away in the exhaust system), and will be graded at half the listed price.
Do not remove the ceramic honeycomb material from the metal shell, as we will not be able to determine the type of converter and the associated value of the raw material. We do purchase ceramic honeycomb material that is not contained in the shell, but the price paid is per pound based on current market prices (and could be substantially lower than the price received if the material was still contained in the original catalytic converter shell).