The catalytic converter is a muffler like device inserted in the exhaust system. Exhaust gases flow through the converter where a chemical change takes place, reducing carbon monoxide and hydrocarbons to carbon dioxide and water; the latter two elements being harmless. The catalysts promoting this reaction are platinum and palladium coated beads of alumina. Because of the chemical reaction which does take place in the converter, the temperature of the converter during operation is higher than the exhaust gases when they leave the engine. However, insulation keeps the outside skin of the converter about the same temperature as the muffler. An improperly adjusted carburetor or ignition problem which would permit unburned fuel to enter the converter could produce excessive heat. Excessive heat in the converter could result in bulging or other distortion of the converter's shape. If the converter is heat damaged and must be replaced, the ignition or carburetor problem must be corrected for.