I unscrewed one bolt on my muffler the other bolt I couldn't unscrew because there was a square nut on top preventing me from unscrewing it. I took one screw out and opened it up a bit so it is loud. By doing that does that effect my car in any negative way? Will it kill the car? My transmission went does that have anything to do with me unscrewing the muffler a little bit?
It may not kill the car but it can kill you, the exhaust fumes are now collecting under the car and can be drawn into the cabin while you drive, the sealed exhaust directs the exhaust out past the danger zone of being drawn into the car, you must fix this asap.