Originally posted by Sandman333:
The law in IL concerning this:
(625 ILCS 5/12-101)
Sec. 12-101. Scope and effect of equipment requirements. (a) It is
unlawful for any person to drive or move or for the owner to cause or
knowingly permit to be driven or moved on any highway any vehicle or
combination of vehicles which is in such unsafe condition as to endanger
any person or property, or which does not contain those parts or is not
at all times equipped with such lamps and other equipment in proper
condition and adjustment as required in this Chapter 12, or which is
equipped in any manner in violation of this Code, or for any person to
do any act forbidden or fail to perform any act required under this
Chapter 12.
(625 ILCS 5/12-602)
Sec. 12-602. Mufflers, prevention of noise.
Every motor vehicle driven or operated upon the highways of this
State shall at all times be equipped with an adequate muffler or exhaust
system in constant operation and properly maintained to prevent any
excessive or unusual noise. No such muffler or exhaust system shall be
equipped with a cutout, bypass or similar device. No person shall modify
the exhaust system of a motor vehicle in a manner which will amplify or
increase the noise of such vehicle above that emitted by the muffler
originally installed on the vehicle, and such original muffler shall
comply with all the requirements of this Section.
(Source: P. A. 77-37.)
This means that, in IL, if your modified exhaust system causes fumes to accumulate in the car, or if it releases a higher sound level than that of the OEM system, it is illegal. It can be readily apparent to an officer on the street that your vehicle is louder than OEM, even without a sound level measuring device.
--- Just the facts.
I know all about that. Got pulled over for that one.
