A catalytic converter (500, 600) for treating a flow of exhaust gas, comprising: a reaction chamber having a first end section through which the exhaust gas flows into the reaction chamber and a second end section from which the exhaust gas exits the reaction chamber; a heating enclosure enclosing at least a portion of the reaction chamber, the heating enclosure being configured to receive a portion of the exhaust gas, defining a heated gas, recirculate the heated gas along the exterior of the reaction chamber and enter the heated gas back into the flow of exhaust gas; a catalytic element in the reaction chamber; and a coolant channel encasing the heating enclosure, the coolant channel being configured to contain a flow of coolant around the heating enclosure, wherein: the reaction chamber has a central conduit between the first end section and the second end section; the heating enclosure has an inner housing having a first portion attached to the first end section of the reaction chamber, a second portion attached to the second end section of the reaction chamber, and a medial portion spaced outwardly apart from the central conduit such that the heating enclosure comprises an enclosed space between the central conduit and the inner housing; and the coolant channel has an outer housing spaced outwardly apart from the inner housing and a flow channel defined by the inner housing and the outer housing. a reaction chamber having a first end section through which the exhaust gas flows into the reaction chamber and a second end section from which the exhaust gas exits the reaction chamber; a heating enclosure enclosing at least a portion of the reaction chamber, the heating enclosure being configured to receive a portion of the exhaust gas, defining a heated gas, recirculate the heated gas along the exterior of the reaction chamber and enter the heated gas back into the flow of exhaust gas; a catalytic element in the reaction chamber; and a coolant channel encasing the heating enclosure, the coolant channel being configured to contain a flow of coolant around the heating enclosure, wherein: the reaction chamber has a central conduit between the first end section and the second end section; the heating enclosure has an inner housing having a first portion attached to the first end section of the reaction chamber, a second portion attached to the second end section of the reaction chamber, and a medial portion spaced outwardly apart from the central conduit such that the heating enclosure comprises an enclosed space between the central conduit and the inner housing; and the coolant channel has an outer housing spaced outwardly apart from the inner housing and a flow channel defined by the inner housing and the outer housing. the reaction chamber has a central conduit between the first end section and the second end section; the heating enclosure has an inner housing having a first portion attached to the first end section of the reaction chamber, a second portion attached to the second end section of the reaction chamber, and a medial portion spaced outwardly apart from the central conduit such that the heating enclosure comprises an enclosed space between the central conduit and the inner housing; and the coolant channel has an outer housing spaced outwardly apart from the inner housing and a flow channel defined by the inner housing and the outer housing.