It is not possible to catch fumes off the end of your car and turn them back into gas. The fumes that come out of your car's exhaust pipe are a mixture of gases and pollutants, including carbon dioxide, water vapor, nitrogen oxides, and hydrocarbons. These gases are the products of combustion, and they cannot be turned back into gasoline.
However, there are devices that can capture some of the pollutants in car exhaust, such as catalytic converters and emission control systems. These devices help to reduce the amount of pollution that is released into the atmosphere, but they do not turn the fumes back into gasoline.
