Exhaust Emissions System - Catalytic Converter: Operation

When exhaust gases pass through the converter the catalyst promotes a chemical reaction to convert unburned hydrocarbons and carbon monoxide into carbon dioxide and water. Engine maintenance is critical on vehicles equipped with catalytic converter as misfiring or excessive richness of fuel mixture can overheat the converter and destroy its effectiveness. Only unleaded fuel can be used with converters as lead can coat the catalyst and reduce its efficiency.