Catalytic Converter: Description and Operation

DESCRIPTION
The three-way catalytic converter utilizes a catalyst to accelerate the recombustion of HC and CO and a catalyst to reduce NOx in the exhaust gas, changing them into harmless CO2, H2O, and N3. In order to maintain mixture ratios at the ``stoichiometric'' point, the point at which the converter works most efficiently, a mixture ratio feedback system is employed. In this system, an exhaust gas sensor monitors oxygen content in the exhaust gases and signals the fuel system to alter the air/fuel mixture to maintain the ``stoichiometric'' level. This air/fuel level should be maintained at a ratio of approximately 14.7 to 1, in order to maintain a high conversion efficiency.