N.D. Cent. Code § 39-21-37: Muffler - Prevention of noise and smoke

1.Every motor vehicle must at all times be equipped with a muffler in good working order and in constant operation to prevent excessive or unusual noise and annoying smoke, and no person may use a muffler cutout, bypass, or similar device upon a motor vehicle on a highway.

2.The engine and power mechanism of every motor vehicle must be so equipped and adjusted as to prevent the escape of excessive fumes or smoke.