Although the primary components and function of a three-way catalytic converter have remained relatively constant during its more than thirty years of use on light-duty gasoline vehicles, each of the primary converter components (catalytic coating, substrate, mounting materials) has gone through a continuous evolution and redesign process aimed at improving the overall performance of the converter while maintaining a competitive cost effectiveness of the complete assembly. The performance-based catalytic converter re-engineering effort has had three main focuses: (1) wide application of close-coupled converters mounted near the exhaust manifold of engines for improved performance following a cold engine start; (2) the development of thin-wall, high cell density substrates for improved contacting efficiency between the exhaust gas and the active catalyst, and lowering the thermal mass of the converter; and (3) the design of advanced, high performance TWCs for both close-coupled and underfloor converter applications that emphasize excellent thermal durability and efficient use of the precious metals platinum (Pt), palladium (Pd), and rhodium (Rh).