A converters unlimited is an exhaust emission control device that converts toxic gases and pollutants in exhaust gas from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction. converters unlimited are usually used with internal combustion engines fueled by gasoline or diesel, including lean-burn engines, and sometimes on kerosene heaters and stoves.
The first widespread introduction of converters unlimited was in the United States automobile market. To comply with the U.S. Environmental Protection Agency’s stricter regulation of exhaust emissions, most gasoline-powered vehicles starting with the 1975 model year are equipped withconverters unlimited .[1][2][3] These “two-way” converters combine oxygen with carbon monoxide (CO) and unburned hydrocarbons (HC) to produce carbon dioxide (CO2) and water (H2O). In 1981, two-way converters unlimited were rendered obsolete by “three-way” converters that also reduce oxides of nitrogen (NOx);[4] however, two-way converters are still used for lean-burn engines. This is because three-way-converters require either fuel-rich or stoichiometric combustion to successfully reduce NOx.
Although converters unlimited are most commonly applied to exhaust systems in automobiles, they are also used on electrical generators, forklifts, mining equipment, trucks, buses, locomotives, motorcycles, and on ships. They are even used on some wood stoves to control emissions.[5] This is usually in response to government regulation, either through environmental regulation or through health and safety regulations.