Exhaust pipe modification is not within the scope of the new regulations. It is still illegal to change it. The soon-to-be-released refitting standards include the refitting standards for automobile exterior enclosure, acoustics, pedals, shock absorbers, wheels and reinforcements, the refitting standards for automobile lighting, interior decoration, color-changing film and luggage rack, the air testing standards for the refitted automobile computer system, circuit, appearance and interior decoration, the safety testing standards for automobile refitting and the reliability testing standards for accessories, with a total of 16 kinds of automobile refitting standards. These standards do not include exhaust pipes.

Increasing the number of exhaust pipes or increasing the diameter of exhaust pipes will lead to the decrease of catalyst efficiency, thus increasing the pollution degree of exhaust gas. At the same time, it will increase the engine power, make the car run faster, make the driving performance mismatch with the body structure, and bring hidden dangers.