Concord L6-258 4.2L VIN C 2-bbl (1982)
Catalytic Converter: Description and Operation
General Description
Fig. 14 Fuel Tank Filler Neck With Restrictor Used On Vehicles With Catalytic Converters
Catalytic converters are used to convert carbon monoxide (CO), hydrocarbon (HC) and oxides of nitrogen (NOx) into water vapor (H2O), carbon
dioxide (CO2) and nitrogen (N2). The catalyst used to create these conversions are platinum, palladium and rhodium (depending on type of
converter).
During engine operation, all of the exhaust gases flow through the converter where a chemical change takes place. This change causes the
temperature inside the converter to be higher than the temperature of the exhaust gases when they leave the engine. Due to this increase in heat, the
converter is insulated so that its outside temperature is about the same temperature as the muffler. However, due to its solid mass, the converter
remains hot much longer than the muffler.
The body of the catalytic converter is made of stainless steel designed to last the life of the vehicle. Excessive heat can bulge or distort the
converter. Since excessive heat built up is not the fault of the converter, the carburetion or ignition system should be checked whenever a converter
is damaged by overheating.
Although all vehicles with catalytic converter must use unleaded fuel, small amounts of leaded fuel can be used in case of an emergency. To
prevent adding leaded fuel, the fuel tank filler nozzle has a built-in restrictor, Fig. 14.
