A catalytic converter apparatus for use in an exhaust system of an internal combustion engine includes a housing having a gas inlet and a gas outlet, and at least one catalytic substrate element disposed in the housing. The at least one substrate element is divided into a plurality of zones or sections, the zones at least partially separated from one another to inhibit heat flow. The zones can be at least partially separated with walls. The walls can include insulating material for reducing the mobility of heat radially outwardly. Each of the zones defines a generally separate flow passage connecting the inlet and outlet in fluid communication. The apparatus can heat more rapidly from a cold start compared with conventional catalytic converters.