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Best Legal Exhaust Mods in Los Angeles (and Where to Get Them)

Unlike the top 10 illegal car modifications in California, it is legal to modify your exhaust so long as you don’t impact your vehicle’s emission system and it isn’t too loud. With California being one of the most progressive states when it comes to environmental policies, it can be difficult to determine which specific mods are legal and which ones are not. Here we will go over the applicable laws when it comes to exhaust mods in California, then overview a few examples and where to find them.

Applicable Laws

When looking into vehicle customization trends right now in Los Angeles, you need to make sure that you won’t make your vehicle fall out of compliance with the relevant laws and regulations. When it comes to exhaust modifications, the main things you need to watch out for is the decibel limits, having a muffler, and compliance with the California Air Resource Board and Environmental Protection Agency regulations.

When looking into exhaust mods, you need to pay attention to how loud they are. The exhaust noise limit in California is 95 decibels. This is pretty good when you consider that a vacuum when you stand next to it is only 70 decibels and the factory exhaust systems of power sports vehicles generally do not exceed 75 decibels. This means you have quite a bit of wiggle room.

 It is also worth noting that any motorcycles manufactured in 1986 or more recently can not have an exhaust system that exceeds 80 decibels. It’s a good idea to keep it a bit under the noise limit because in the State of California, police officers are able to use their judgment to determine if someone’s exhaust is too loud.

According to the California Vehicle Code Section 27150 (a), “every motor vehicle subject to registration shall at all times be equipped with an adequate muffler in constant operation and properly maintained to prevent any excessive or unusual noise, and no muffler or exhaust shall be equipped with a cutout, bypass, or similar device.” An example of something that would not be accepted under Vehicle Code Section 27150 is a whistle tip since it would cause not only loud noise but also unusual noise.

The last thing you have to worry about staying in compliance with is the California Air Resource Board and the Environmental Protection Agency. Luckily, determining if an exhaust system is acceptable in California is less difficult than figuring out if tuning is illegal in California. If your vehicle’s factory exhaust system doesn’t contain a catalytic converter, then an aftermarket exhaust part is considered a replacement. This is only true if it does not remove or replace something like the oxygen sensors because this can alter the emission control system.

If your vehicle’s factory exhaust system does contain a catalytic converter in the manifold portion, an aftermarket muffler positioned after the catalytic converter is considered a replacement. To be extra sure, you can look up if a part is accepted by the California Air Resource Board through their executive order lookup which lists all acceptable aftermarket parts.

PaceSetter Performance Product’s Exhaust Header by Summit Racing

Exhaust modifications are often specific to a group of vehicle’s but one of the best for trucks and SUVs is PaceSetter Performance Product’s Exhaust Header. This exhaust header is made specifically for many makes and models, some of which include Broncos, some GM V8s, some Chrysler V8s, and some Ford trucks and SUVs.

This particular exhaust modification does more than affect the sound of your vehicle, actually providing for up to 15 extra horsepower, as well as significantly increasing your vehicle’s torque in the 1500 to 3500 rpm range. With this exhaust mod, you would not have to worry about how to pass the emissions test with a modified car in California since the California Air Resource Board found that this exhaust header does not reduce the effectiveness of the applicable vehicle pollution control systems and therefore, is exempt from the prohibitions of Vehicle Code Section 27156. You can check out more about this exhaust header at Summit Racing’s website here.

Stainless Steel Touring 2 ½ “ Cat-Back Exhaust System

Ford Performance Stainless Steel Touring 2 ½ “ Cat-Back Exhaust System by Borla is a great, though pricy, exhaust modification that is perfectly legal in the state of California. This cat-back exhaust system is made specifically for 2015, 2016, and 2017 GT Mustangs and gives them a more robust sound.

2015, 2016, and 2017 GT Mustangs have exceptionally quiet factory exhaust systems, leading to many muscle car enthusiasts desiring a more powerful sounding exhaust to match their 5.0L V8 engine and this exhaust mod does exactly that. Since this cat-back exhaust system bolts directly into your factory catalytic converts, this exhaust system is completely compliant with all of California’s Air Resource Board and Environmental Protection Agency regulations.

Helping your Mustang sound as good as it runs is not the only use for this exhaust modification, it also has a superior appearance according to many. This exhaust system can be found on JC Pony Parts’ website here.

Wrapping Up

The exhaust modification you decide to get will depend on the make, model, and year of your vehicle, along with what you intend to get out of it. No matter what you decide to get, you have to be aware of the relevant laws and regulations.

First, you must make sure that you have a muffler as part of your exhaust system that prevents the exhaust system from making an excessive amount of noise or unusual noise. The noise limit in California is 95 decibels, except for motorcycles where the noise limit is 80 decibels. You also need to make sure you stay in compliance with the California Air Resource Board and Environmental Protection Agency. You can do this by checking for EO numbers. 


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