Exhaust Noise Laws in Oregon?

Ello~ I’m going to be relocating to Portland OR in the coming months… I currently have a Mustang I’m modifying somewhat heavily to be a fun track and touring car… I heard OR has some laws about exhaust noise but I can’t find anything specific

I plan on adding long tube headers, Magnoflow catback exhaust system, new manifolds… Which will increase the noise… I wanna know if this’ll get me in trouble or is this one of those things where the law exists but no one ever gets charged?

I live in CA now, which has a rather strict exhaust noise law, with a limit of 95 dbA which apparently makes 80-90% of factory stock performance cars illegal… But even so there are seriously modified loud monsters all over, going passed cops without a problem

I’m a pretty conscious driver in terms that I’m not one to wake the neighbors or disturb the peace, also I work from home so I don’t generally leave in the early hours either… Will I be fine? Again is this just one of the laws that kinda exists but not really?

So far the best info is what i’ve found from SEMA’s network


Oregon Revised Statutes

§ 815.250 Operation without proper exhaust system; exemptions; penalty.

(1) A person commits the offense of operation without proper exhaust system if the person drives or moves on any highway or owns and causes or knowingly permits to be driven or moved on any highway a motor vehicle that is not equipped with an exhaust system that meets the requirements under this section.

(2) An exhaust system only meets the requirements of this section if all of the following apply:

(a) The exhaust system must be in good working order.
(b) The exhaust system must be in constant operation.
© The exhaust system must meet noise emission standards determined by the Department of Environmental Quality to be substantially equivalent to the following standards based upon a stationary test conducted at a distance of 25 feet in accordance with procedures established by the Department of Environmental Quality:

I. Vehicle type: Motor vehicles required to establish a registration weight under ORS 803.430 and commercial buses
Maximum level, dBA: 94 dBA if model year before 1976; 91 dBA if model year 1976 and after

III. Vehicle type: motor vehicles not described under I or II
Maximum level, dBA: 92 dBA if model year before 1976; 88 dBA if model year 1976 and after

(3) This section does not apply to the following vehicles:
(a) Vehicles of special interest that are registered under ORS 805.020 and that are:
(A) Equipped with original manufacturer’s equipment and accessories, or their equivalent, and that are maintained in safe operating condition; or
(B) Street rods that conform to ORS 815.107.
(b) Road machinery, road rollers or farm tractors.
© Antique motor vehicles that are maintained as collectors’ items and used for exhibitions, parades, club activities and similar uses, but not used primarily for the transportation of persons or property.
(4) The court in its discretion may dismiss a citation issued for violation of the offense described in this section if evidence is presented that the exhaust system complies with or has been repaired or modified to comply with the requirements under this section.
(5) The offense described in this section, operation without proper exhaust system, is a Class C traffic violation.


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All states do, but if your car currently passes CA inspection, it should have no problem going to OR.

Don’t make the exhaust replacement until after your Mustang is registered and licensed in Oregon. It looks like Oregon only has emissions inspections, even for newly titled and registered vehicles. That should keep them from busting you for too much noise, but I don’t live there and don’t know.

Headers replace the manifolds. Be sure to check with Oregon to make sure they don’t require CA certified parts because headers and catted X pipes will not comply.

Be sure and install the catted X or H mid pipes when the headers go in so you will pass emissions.

Another vote for waiting until you actually live in Oregon. Why take a chance that the Department of Motor Vehicles will not let you license the modified vehicle . An Oregon speed shop and a muffler shop will guide you on the things that are legal .

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I know all states do, but some are worse than others… As my post says, my car has not yet been modified…

My car is already OR registered since my dad’s business is based there… We we saved on the insane sales and registration taxes/fees doing so

My car is already registered in OR under my dad’s business which is located there…

So if my car is already registered, then I don’t really need to worry then? is that what you’re saying?

I have no idea what this means…

To the exhaust system law in Oregon.

It appears that unless this qualify’s under the street rod exemptions you’re limited to 88dba but It’s not clear if you can be pulled over just for a loud exhaust.

Yeah I understood that… What I really wanna know is if people even get cited for this? That’s what I meant by a law that exists but kind of doesn’t… But I guess as long as you don’t disturb the peace, I should be fine

You’ll have to find that out from people in OR. Many traffic laws across this country are not enforced. Here in NH (and many others) there’s actually a law on how much you can lift your truck. I’ve seen plenty of trucks lifted well beyond those limits.

Yeah, people have gotten cited for it before. Usually it’s when the cop wants an excuse to give someone a hard time. i.e, a teenager driving foolishly but not crossing the line to illegality, but he’s got a loud car…

That said, consider your neighbors and their opinions of you if your car is obnoxiously loud. My next door neighbor’s kid decided to make his car sound like a race car, and guns it around the neighborhood all day and night, and the rest of us neighbors are not pleased about it.

Yeah I guess once I go to the racetrack there I should be able to get some answers…
I watched a video from Donut Media on weird traffic laws that still exist… pretty wacky stuff… But none are really enforced

Yeah that makes sense…

Oh for sure, I’ve been on the tail end of that kinda BS too… I leave my loudness for the highways and tracks… At the end of the day, when you have a car like that, you need some sensibility… Or else you’re just a spoiled asshole

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I was on a business trip to Phoenix and saw a full size pickup parked where we went for lunch. It was so high that most cars would slide under the bumper on either end. I know that’s illegal in many areas, not sure about Arizona.

Only 2 counties in Oregon require emissions testing. Multnomah due to congestion and Jackson due to it’s largest city being located in a ‘hole’ creating smog problems.

I was differentiating between smog inspections and safety inspections for newly registered vehicles. I may not have made that clear enough. Some states have the safety inspections, and it appears that Oregon is not one of them.