Exhaust thats Legal in CA
 

Maybe in the next several months, I want to add a new exhaust to remove that drone in the higher RPM range. But from what I read, nothing is legal in the great state of CA. So I am asking for some help and guidance.

Pretty much anything from the cat back is legal, as long as it doesn't exceed the 95 dB limit

Thank you sir :)

^ This. Headers will need to be CARB legal and I'm not sure what's the deal with cats. Might not be legal to change at all. I know running a test pipe/catless is more illegal then just a fix it

How about changing the over pipe? Also the front pipe (with cat)? Can you pass smog with that?

Tap'd from my G-Nex

Let me clarify my original post. Anything past the cats is ok to change. The stock cats have to remain. Technically, you are not allowed to change the cats at all unless one is damaged and that gets annotated when changed. Anything between the cats and the engine would require a CARB approval afaik.

It is illegal to modify your exhaust in California. That is why after market exhaust systems come with the "For Offroad Use Only" tag. CARB prohibits ANY exhaust part that is not stamped with an OEM indicator OR a CARB exemption. Then there is the 95 decibel rule. (Ironic if you drive at Laguna Seca where they will black ball cars for 92 or 93 decibels)

Having said this...

Catback exhaust that isn't super loud may get by a SMOG check if the tech doesn't fail you during the visual inspection.

Headers with higher flow rate cats may pass emissions if the car is properly warmed up, but are still illegal.

Anything that you do to your car that could possibly affect emissions needs a CARB exemption sticker. In the BMW world, Dinan was one of the few companies that jumped through the hoops with the State to get certified. They used to sell Vortech superchargers for twice the going rate because they were CARB certified.

Laguna Seca only imposed this db rule as a result of all the retirement communities that popped up around there in recent years, thus the voters imposing that law. Hence why, as one of the greatest tracks out there, you don't see any major race series driving there anymore.........not like Nascar could handle the corkscrew anyways

Anything after the last cat is fine. I've never been harassed at smog checks or the police for anything after the last cat.

Also, after (iirc) 02 high performance cats can only be used on track cars. I think it reads that you can have it on the way to and from the track. But look it up as im not 100% on wording.

cat back exhausts are primarily to improve the sound and sometimes make a little more power/torque. They have no effect on emissions. I have 3 cars with cat back or axle back exhausts, and i've taken them all to a test only smog place (which you'd think is more stringent than a normal smog place). The smog guy would actually compliment on the sound of the exhausts, so he clearly knew they were not stock, and they all passed. No doubt every smog place is different but that's my experience.

What I'm curious about is if I get a high-flow cat front pipe to replace the restrictive OEM cat, will it pass the CA emissions test? I know a lot of them are 49-state legal (which means not CA), but not sure if that means it will exceed the emissions limits in CA or just a technicality.

What makes it interesting is that from what I've read the smog test is getting simplified next year, for newer cars there may be no emissions test, just hook up the car to an OBD-II reader and if there are no check engine/fault codes, and you pass the visual, then you pass. If the smog guy only looks under the hood and doesn't look under the car then everything up to the headers would probably pass visual if it doesn't stand out too much.

^This^ 95 decibel limit for all aftermarket exhaust. Thank you SEMA Action Network.


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That isnt really true, though there are many police officers in CA that believe this as well...

They will issue a ticket with the words "modified exhaust" whitten as the description, but the penal code number is for exessive sound (above 95 DB) most folks just pay the ticket and move on, thus perpetuating the "illegal to modify exhaust" myth.

If a modified exhaust was automatically illegal in CA, then every muffler shop in town would instantly be out of business. (they are not, there are a TON of exhaust shops around here) a law like that wouldnt even really make sense in the real world, as exhaust systems need periodic replacement, and the dealership is really not interested in dealing with it.

All that being said, there ARE specific laws regarding sound levels, and since the local PD doesnt equip every car with a meter, it is up to the individual officer, which works against the twins, as they have a very unusual exhaust note, that not everybody loves.

Also, anything with emmisions equipment built into it, (such as the catted exhaust manifold or front pipe), must either be OEM, or replaced with a CARB approved alternate, with the appropriate CARB exemption sticker displayed under the hood.

This is incorrect.