Exhaust system Law in the United States and other countries to not have a catalytic converter. Converters may not be removed from a vehicle that is used only for "off-road" driving in the United States. The main purpose of a catalytic converter on an automobile is to reduce harmful emissions of hydrocarbons, carbon monoxide and nitrogen oxides into the atmosphere. They work by transforming the polluted exhaust components into water and carbon dioxide. Cat-back (also cat back and catback) refers to the portion of the exhaust system from the outlet of the catalytic converter to the final vent to open air. This
Diesel exhaust Emissions from diesel vehicles have been reported to be significantly more harmful than those from petrol vehicles. Diesel combustion exhaust is a source of atmospheric soot and fine particles, which is a component of the air pollution implicated in human cancer, heart and lung damage, and mental functioning. Moreover, diesel exhaust contains contaminants listed as carcinogenic for humans by the IARC (part of the World Health Organization of the United Nations), as present in their List of IARC Group 1 carcinogens. Diesel exhaust pollution is thought to account for around one quarter of the pollution in the air in previous