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
Steam car steam engine conversions for existing production cars. When air pollution became a significant issue for California in the mid-1960s the state encouraged investigation into the use of steam-powered cars. The fuel crises of the early 1970s prompted further work. None of this resulted in renewed steam car manufacturing. Steam cars remain the domain of enthusiasts, occasional experimentation by manufacturers, and those wishing to establish steam-powered land speed records. In 1967, California established the California Air Resources Board and began to implement legislation to dramatically reduce exhaust emissions. This prompted renewed interest in alternative fuels for motor vehicles and a resurgence