Exhaust emissions are comprised of CO, hydrocarbons (HC) and Nitrogen oxides (NOx). Which from gasoline engine operations. Gasoline engine operation is controlled at vary narrow air/fuel ratio which is close to proper value, so the emissions of CO, HC and NOx can be removed simultaneously on three way catalytic converters. Three-way catalytic converters are based on the proprietary catalyst formulation of precious metal (PdPTRh) and the transition metal coated on ceramic honeycomb substrates. Three-way catalytic converters use precious metal and the transition metal in low cost and has high removal efficiency of CO, HC and NOx and high stability. The product through the examination, has achieved the European III standard. Three-way catalysts are designed to simultaneously convert