An exhaust gas valve assembly includes a housing defining a cavity therein and having an intake port and an exhaust port. A valve seat has a first axial end secured to the housing and a second axial end that is disposed within but decoupled a distance from the housing. The second axial end defines one or more apertures that provide fluid communication between the intake and exhaust ports. A seal is disposed between the second axial end of the valve seat and the housing so as to close the decoupled distance therebetween. A piston is received within and is axially movable relative to the valve seat so as to open and close the one or more apertures and thereby regulate exhaust gas flow between the intake and exhaust ports.
