Clean Air Technologies

Catalytic Converters
Most cars are sources of pollution, and to keep up with emissions laws automakers began refining car engines and fuel systems in the 1970s. These modifications culminated in catalytic converters, which treat exhaust before it leaves a car's tailpipe, converting toxic combustion by-products such as carbon and nitrogen monoxides to less-toxic gases. Catalytic converters have been highly successful in reducing emissions, but substantial increases in the distances cars and trucks travel on average and in the overall number of vehicles in use have made up the difference, and cars are still a major cause of pollution.