Repair 7

How Does a Catalytic Converter Work

Catalytic Converter as Afterburner

The sole job of a catalytic converter is to reheat already-burned exhaust gases from a cars engine. As burned engine fuel, or exhaust, leaves a cars engine, it travels along a cars exhaust system. A catalytic converter is located in the middle portion of the exhaust system--between the engine and the tailpipe. Exhaust gas flows directly into the catalytic converter and is reignited and reburned to reduce emissions.

Catalytic Converter Makeup

The outside of a catalytic converter looks just like a car muffler. It is sort of oblong with an aluminum outer cover. A cars exhaust pipe flows directly into a catalytic converter, which houses a catalyst that is superheated by the flowing exhaust gases and ignites the incoming exhaust gases. This catalyst is usually made up of small pieces of palladin, a heat-reactive element that turns glowing hot when heated.

Reduction of Exhaust Emissions

As exhaust gas exits a catalytic converter and flows toward the cars tailpipe, the vehicle emissions are much lower than they were before entering the catalytic converter. Due to the heating and re-igniting effects of the catalyst elements on the exhaust gases, much of the unburned or improperly burned fuel is burned in the catalytic converter and prevented from exiting the cars tailpipe into the outside air. This greatly reduces vehicle emissions.

Unleaded Gas Only

All cars equipped with catalytic converters require the use of unleaded gas only. The catalyst elements inside a catalytic converter are highly sensitive and can be damaged by gas that contains lead. Catalytic converters were first installed on American cars in 1975, the first year of unleaded gasoline.