Catalytic converters have been used since mid 1970’s in order to reduce toxic emissions from gasoline cars.

The most advanced catalytic converters, called Three Way Catalysts, have been made mandatory in United States since 1976.

In this type of converters, 3 types of toxic emissions: carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide are converted into non-lethal emissions such as: steam (H2O), nitrogen (N) and carbon dioxide (CO2).