HCC §24-111
Rules for modified exhaust systems on public roads
Read the official text at hawaiicounty.gov ↗This section says you cannot drive a vehicle on a public road if its engine or exhaust has been changed to make too much noise, or if it has a fake muffler or a device that lets exhaust bypass the muffler. It is about keeping vehicle noise down.
everyone
The ordinance, as written (Hawaiʻi County) — Modified or altered exhaust systems
A copy, taken August 21, 2026. The version published by Hawaiʻi County is the one that governs, and it may have changed since. Check it before relying on anything here.
No person shall operate on a public highway or street a motor vehicle (a) with a motor or exhaust system which has been altered or modified to such an extent that the noise emitted by the motor or exhaust system shall be deemed excessive or unusual or (b) equipped with a dummy muffler, cut-out by-pass or other similar device. Division 6. Signal Devices.
Published by the County of Hawaiʻi Office of the County Clerk.
LawTrove is not legal advice. The summary above is a computer-generated restatement — the authoritative text is the official version linked above.