My bro was in a rush to work the other day and he reversing out of our driveway which is pretty steep and accidently put the car into first gear while the car was still going backwards at around 6-10 miles an hour and he heard a loud pop noise. He has a 98 civic dx (5 speed). Since then there is a very strong smell of gas like a gocart smells kinda and the car shakes now when you are not moving. It is also very studery when accelerating. Does anyone have any idea what is wrong with it or what coulda happened cuz have no idea. thanks.