ORS 811.492: Engine braking; penalty; exception.

(1) A person commits the offense of engine braking if the person is operating a motor vehicle on a highway and uses an unmuffled engine brake. (2) The offense described in this section, engine braking, is a Class A traffic violation. (3) A person is not in violation of this section if the person uses an unmuffled engine brake in an emergency situation to avoid imminent danger to a person or to property. [1993 c.314 §7]