Hong Kong Regulations

ROAD TRAFFIC (CONSTRUCTION AND MAINTENANCE OF VEHICLES) REGULATIONS - REGULATION 30

Silencers

(1) Every vehicle propelled by an internal combustion engine shall be fitted
with a silencer, expansion chamber or other contrivance suitable and
sufficient for reducing, as far as may be reasonable, the noise caused by the
escape of the exhaust gases from the engine.

(2) Every vehicle propelled by an internal combustion engine and used on any
road shall be so constructed and maintained that the exhaust gases from the
engine shall not escape into the atmosphere without first passing through the
silencer, expansion chamber or other contrivance required to be fitted under
paragraph (1).

(3) Every such silencer, expansion chamber or other contrivance shall at all
times while the vehicle is used on a road be maintained in good and efficient
working order, and shall not have been altered or replaced in such a way that
the noise caused by the escape of the exhaust gases is made greater by the
alteration or replacement.