Abstract: An exhaust muffler includes upper and lower internal plates and upper and lower external shells. The internal plates are formed to define a chamber therebetween. The external shells are formed to define chambers on opposite respective sides of the interconnected internal plates. An upper tube plate is secured to the upper internal plate. The upper tube plate and the upper internal plate are formed to define an inlet tube therebetween. The inlet tube includes louvers to permit exhaust gas flow into the chamber between the upper internal plate and the upper external shell. Louvers in the upper internal plate permit exhaust gas to flow from the upper chamber into the internal chamber between the internal plates. Louvers in the lower internal plate permit exhaust gas to flow into the lower chamber. An outlet tube communicates with the gravitational low point in the lower external shell and permits flow of exhaust gas from the muffler while siphoning condensate in the lower chamber.