It is illegal in IL to modify or replace your exhaust with anything other than oem hardware or with anything that increases the volume of the oem exhaust. There is no decibel requirement.

(625 ILCS 5/12‑602) (from Ch. 95 1/2, par. 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.)

 

Looks to me like you have to prove that your replacement hardware does not produce more noise than the OEM equipment. No easy task! You would have to have credible proof such as readily accepted sound measuring and recording equipment and a stock car to record as well.

Even then, you may be boned.

 

Motorcycles are allowed a higher DB than Automobiles...

 

like the post above says, it is illegal to have any modified mufflers installled in the state of IL. Now if someone can come out with a super quiet 3in exhaust it shouldn't get any attention in all these states that have this requirement

 

thats not fair if its true. well i never like the sound of a harley anyways

 

I had mine back in the day on my cavvy and right here in the burbs of chicago cops never pulled me over . Once for having my subs thumping but he gave me a warning.

 

i now keep my silencer with me in the car b/c i have been pulled over one too many times leaving my g/fs house for loud exhaust

 

All vehicles have diff guidelines .. If a moped sounds like a harley, he will get pulled over.. And if an evo sounds like a peterbuilt deaccelerating with his jake brake on, he will get busted.. lol What I always say when I get pulled over ... (since I have the buschur tbe not a huge can, with a cat which is still loud enough to get harassed) Is you can go ahead and give me a ticket... this is an oem exhaust. They dont like that at all.. And I have gotten nothing but warnings from all diff cops.. not one ticket.. Is it a lie .. yes ... But they are just hoping when they walk up to your window, that your drunk/high/suspended license .. When you come back clear.. that pisses them off.. So I play the game.. And I havent loss yet!

 

If this law is to keep noise levels low, as I imagine it is, then everyone driving on the road should have to abide to the same dB level, no exceptions.

There is no difference if you disturb "the peace" by having a 3" exhaust on an Evo, or a Harley with a factory straight pipe, noise is noise. This is what p1sses me off!!!

 

Not true, if you knew what a stock harley sounds like you would think it was a honda. Everyone that rides a harley the first thing they do is change the pipes to get that sound.

 

This is why now I changed back to stock catback. It is worth losing 20whp. After I changed back to stock catback, cops never notice that I am fully modded.

I would suggest keeping the noise down for the general public, Only people enjoying the noise is you and very very few enthusiasts. My friends, relatives and coworkers hated me for that noise. Normal people don't enjoy the exhaust sound.

The exahust sound is music to our ears though...

 

you would think cops would have better things to do then give tickets for the stupidest things like a loud exhaust, too big a spoiler, tail lights tinted incorrect color. i have yet to have a problem where i am but i do hear about these alot and cops need to get off thier ***'s and do some actual work like stopping real crims where people are actually in need of help.

 

no need to hate cops they have to do their job even that means pulling us over. I'm not supporting on how we get profiled every time we pass them but they still have a job to do.

 

We would need more criminals for them to get off their *** and do some actual work.

LA used be like that. I saw bullet holes on many police cars and trashed police cars on the side of the road...

But not anymore, people are tamed and Cops need more criminals to get their pay check so They are actually trying to make criminals out of innocent people like us. That exhaust law is a joke

 

I was profiled last week. Cop told me there was 3 reasons he pulled me over:
1) Missing front plate - it's there; he apologized after rechecking.
2) Windows looked tinted - yep; and proud of it, I know they're too dark too. He told me I wasn't allowed to tint the fronts at all - which isn't correct
3) Exhaust looks modified - yep it is, but it's totally legal. Running a HR cat and a quiet magnaflow exhaust; it's not loud at all. He made me 'rev it up a bit' and I swear this was his exact words:

"Well, that's not as loud as the last one of these cars I pulled over"

Can you say profiling????