A powertrain control system (10) is provided that includes an engine (12) having multiple cylinders (14). A controller (24) selectively activates the cylinders (14) to provide a cylinder combination having a desired power displacement. In one example powertrain control system (10), the controller (24) selectively activates the cylinders between a V-8 and V-4 mode. An exhaust system (17) having a valve (28) and an electrical actuator (26) selectively electrically actuates the valve (28) in response to the controller (24) between multiple positions. The electrical actuator (26) moves the valve (28) from an open position in V-8 mode to a partially closed position in V-4 mode to increase back pressure and reduce noise, vibration and harshness issues in V-4 mode. A muffler (20) includes a housing (30) having an exhaust passage. The valve (28) is supported by the housing (30) and arranged in the exhaust passage. The valve (28) is moveable between multiple positions for tuning the muffler (20). The electrical actuator (26) is supported by the housing (30) to actuate the valve (28) between the multiple positions.