((Stock Cat-back)) ((Stock Cat-back)) ((Stock Cat-back)) Serious buyers only, please. Sierra 2014-2018 Cat-back (Stock Cat-back). It has a modification with a 3-inch steel pipe connected from the y-pipe to after the stock muffler, then connected to the exhaust itself to make the sound come out from the end of the exhaust. Before the stock muffler, an original valve from Fox company was installed. When the valve is closed, the air goes through the pipe connected to the stock muffler, so the sound is muffled and becomes like the stock sound. ((In short, it's like the sports cat-back system)) ((But I did it so that if the traffic police look under the car, they see the stock muffler)) ((The sound is very good and the tone is excellent)) There is a video detailing the work and sound for serious buyers only. The price is negotiable. (I accept trades for similar systems like Corsa, BTM, or Bolt-back) Mobile number / ( Phone number appears when clicking the contact button )