Abstract: An exhaust afterburner for positioning in an exhaust duct or the like of an internal combustion engine through which partially reacted gases are circulated is disclosed. The exhaust afterburner includes a venturi induction member which has a circumferential array of radially extending apertures for inducting a reacting gas into the exhaust duct upon passage of the partially reacted gases therethrough. A housing surrounds a venturi induction member and includes a first air intake opening in communication with the apertures of the venturi induction member as well as a second air intake opening disposed adjacent to the inlet end of the venturi induction member. A bushing is positioned within the housing at the second air intake opening with the bushing having a circumferential array of radially extending apertures in fluid communication with the second air intake opening. A mechanism for relieving back pressure is provided within the exhaust afterburner positioned within the exhaust afterburner housing.