A replacement kit enables a user to generate a desired audible sound from an exhaust system of a motor vehicle. The kit includes a replacement catalytic converter arranged to replace the vehicle's original equipment catalytic converter. The replacement catalytic converter is connected to the vehicle's factory muffler through a replacement pipe segment to obtain a more desirable, yet muffled engine sound. The factory muffler may be removed from the motor vehicle and the replacement catalytic converter may instead be connected to a muffler bypass pipe or pipes or replacement exhaust components/segments which channels the exhaust flow directly to the atmosphere to obtain a more powerful unmuffled exciting visceral sports car engine sound.