The present teachings provide for a catalytic converter for modifying the composition of exhaust gas of an engine. The catalytic converter includes a housing, a substrate body, and a first layer of catalyst material. The housing can define an inlet for receiving the exhaust gas from the engine, a main chamber in fluid communication with the inlet, and an outlet in fluid communication with the main chamber for exhausting the modified exhaust gas. The substrate body can be disposed within the central chamber and can define a plurality of flow channels. The flow channels can provide fluid communication between the inlet and the outlet. The first layer of catalyst material can provide a first section of the flow channels with a first overall wall thickness that is greater than a second overall wall thickness of a second section of the flow channels.