<P> As an alternative, catalytic converters were moved to a third of the way back from the engine, and were then placed underneath the vehicle . </P> <P> A 2 - way (or "oxidation", sometimes called an "oxi - cat") catalytic converter has two simultaneous tasks: </P> <Ol> <Li> Oxidation of carbon monoxide to carbon dioxide: 2 CO + O → 2 CO </Li> <Li> Oxidation of hydrocarbons (unburnt and partially burned fuel) to carbon dioxide and water: C H + ((3x + 1) / 2) O → x CO + (x + 1) H O (a combustion reaction) </Li> </Ol> <Li> Oxidation of carbon monoxide to carbon dioxide: 2 CO + O → 2 CO </Li>

When did they stop putting catalytic converters on cars