4789 E. Wesley Drive, Anaheim, CA 92807

Frequently Asked Questions
Emission Laws And Regulations

Important Update: January 1, 2009 - Replacement Catalytic Converters For Use In California


Sema Action Network

What is the difference between the Environmental Protection Agency (EPA) and the California Air Resources Board (CARB)?

The EPA is a federal governmental agency that works to develop and enforce regulations that implement environmental laws enacted by Congress. CARB is a California governmental agency that promotes and protects public health, welfare and ecological resources through the reduction of air pollutants.

What agency establishes the laws that affect the emissions controls on my vehicle?

The State of California has long been recognized as one of the major air pollution problem areas in the United States. CARB was established in part to study this problem and implement changes to reduce air pollution. CARB has been leading the nation in implementation of strict emissions requirements for motor vehicles through the use of emission control devices and biannual motor vehicle smog-check program. Vehicles that are labeled as "California Emissions Equipped Vehicles" vehicles meet the emissions requirement of CARB for that particular model year.

The EPA establishes the pollution laws and regulations for states other than California. Vehicles that are labeled as "Federal" emission equipped vehicles meet the emissions requirement of the EPA for that particular model year.

Have other states adopted the California emissions laws?

In recent years, other states have suffered similar air pollution problems similar to those that faced California. Instead of these states enacting their own set of emissions laws, the federal government offered the California laws as an alternative. Instead of having 50 different sets of emissions laws, states must choose between either the California or Federal regulations. However, President Obama has indicated his willingness to allow states to set their own independent standards. Until this takes effect, the impact of this decision is unknown.

At the present time there are several states that have enacted the California laws (i.e. Massachusetts, Maine, New York, New Jersey, Vermont, Arizona, Connecticut, District of Columbia, Maryland, New Mexico, Oregon, Pennsylvania, Rhode Island, and Washington) and new vehicles are sold as "California Emissions Equipped Vehicles". You can easily determine the emissions status of your car by referring to the emissions decal that is placed under the hood of your car.

Is my vehicle required to be submitted to a tailpipe emissions "smog-check?

This depends on the state that you reside in and the local requirements. For example in California, smog-checks are required in populated areas, but not in selected rural areas. With laws and regulations changing at an increasing rate, it is very difficult for the aftermarket to keep ahead of these changes. We suggest you contact your local or state agencies for information regarding your emissions laws. For a listing of state-by-state vehicle emissions inspection requirements and exemptions, see Vehicle Emissions Inspection Requirements By State.

Can I legally replace an emissions sensitive part on my car with an aftermarket product?

In the state of California, it is not legal to replace an emissions sensitive device without the replacement part having an exemption from CARB. Although replacing a particular device might have no apparent effect on the emissions, and the car might even pass a tail pipe "smog-check", the replacement part is still not considered emissions legal. In many cases, the mandatory visual inspection of the vehicle prior to an official state required smog-check may result in immediate failure of the test if a non-exempt part is identified.

A part that has been issued a CARB exemption has been subjected to strict laboratory testing as required by CARB in order to demonstrate that the replacement part will not increase emissions. (These tests are NOT the same as the "smog check" test and often require "cold start" testing procedures in order to test the efficiency of the emissions system during the initial seconds of the start-up cycle.) A part that has successfully passed these tests will be appointed an Executive Order number and will be listed on the CARB website for reference. Every Executive Order part or modification has an assigned number that can be verified by Smog Check stations, BAR Referee stations, or by CARB. This number should be displayed on or near the emissions sensitive part for reference by a smog check technician.

For a database listing of current exempt parts, visit:

What does it mean when an aftermarket product is advertised as "CARB Exempt", "49-State Legal" or "50-State Legal"?

Although a part may be advertised as "49 or 50 State Legal", this may be more of a marketing statement than reality. Unless an emissions sensitive part has been issued an Executive Order number by CARB, or satisfies the requirements of the Federal Clean Air Act, FOR THAT SPECIFIC VEHICLE OR ENGINE CLASSIFICATION, the part is NOT legal for street use. Period, end of statement! If you must have a CARB exempt component for your vehicle, obtain the exemption number from the manufacturer prior to your purchase and verify the application status at the CARB link above.

Parts that are typically appointed CARB exemptions include: headers, air filter/intakes, turbo kits, and supercharger kits, etc.. Parts that are typically not eligible for a CARB exemption include, but are not limited to: ODB-II universal replacement catalytic converters, downpipes or headers that remove or relocate a catalytic converter, and performance carburetor kits. Contact the manufacturer of a product that you are considering purchasing for details regarding that specific component.

An exhaust system that is installed AFTER the catalytic converter is considered a "cat-back" system and is considered emissions legal. (Sound level restrictions may be an issue in your state, check with the exhaust manufacturer or you local authorities for more information.)

With regards to Federal vehicles, per SEMA (Speciality Equipment Market Association), "Obtaining emissions compliance status in California, based on the requirements of the California Air Resources Board (CARB), also satisfies the requirements of the Federal Clean Air Act. As a result, emissions-related parts that become legal for sale in California are legal for sale in all other states. Compliance is based on securing a CARB Executive Order (EO) based on test data demonstrating that a vehicle will continue to comply with emissions standards when an aftermarket add-on product is installed. Furthermore, no emissions-related parts may be legitimately labeled "49-state legal” if a recognized testing process has not been undertaken. The U.S. Environmental Protection Agency (EPA) has a requirement (Memorandum 1A), which states that manufacturers have a reasonable basis for concluding their products do not adversely affect the emissions of the vehicles on which they are to be installed. Currently, the EPA recognizes a CARB EO as meeting the required "reasonable basis." An alternative method for demonstrating a reasonable basis for EPA recognition of a 49-state claim would be testing to the Federal Test Procedure, including durability tests."

Can I replace the OEM catalytic converter on my car with a "high flow" catalytic converter?

Update: 1/1/09 - New catalytic converters sold or installed in CALIFORNIA must be designed to meet the following requirements:

  1. Must be an OE equivalent replacement only - no "high flow" or performance cats
  2. Must be granted an ARB exemption
  3. No used or rebuilt used catalytic converters can be installed

Briefly, this means that you are now required to obtain a new ARB-exempt catalytic converter for your specific vehicle if you require a replacement. The street use of aftermarket performance "high flow" units and aftermarket mid-pipes with non-exempt cats are not legal in CA. For more information on this legislation, visit: Aftermarket Catalytic Converters

The catalytic converter plays a major role in the emissions reduction of a motor vehicle. The vehicle manufacturer has matched a specific catalytic converter to the vehicle to minimize emissions output. Both CARB and the EPA do not allow the replacement of a catalytic converter with a non-exempt "high flow" performance replacement unit. In fact, it is technically not legal to even replace a catalytic converter unless it has been proven by a technician to have failed, and then it can only be replaced with an exempt OEM equivalent unit. (However, enforcement of this requirement is difficult and is the primary loop hole that allows the usage of so-called "high flow" catalytic converters. Many of these units are sold with the disclaimer as being a "race" component and are not intended for street use.) Due to the hundreds of vehicle models produced over the years, it is virtually impossible to determine by glancing under a car whether the converter is the original unit, a legal OEM replacement, or a non-legal aftermarket "high flow" performance unit. However, changing regulations require imprinting the exemption number, manufacturer code, and manufacture date, making it easier for technicians to determine the origin of the product and the intended application.

Can I remove my stock exhaust manifold/catalytic converter and replace them with a header/catalytic converter combination on my RX-7?

Not legally. As mentioned above, CARB or the EPA does not allow relocation of any of the stock catalytic converters. They require that all original catalytic converters be in their original positions, and replacement of multiple catalytic converters with a single non-exempt "high flow" performance unit is not allowed.

Although using a header (or downpipe) and catalytic converter combination might pass a tailpipe test at a California tailpipe emissions test, it would NOT pass the visual inspection portion of the test. Since the engine configuration of the rotary engine in the RX-7 is rather unique, it is possible that some test station technicians may not be familiar with the this layout, and they may not even notice that a header (or downpipe) and/or replacement catalytic converter has been installed.

Why are some aftermarket products are labeled with the following phrase, "Legal in California only for racing vehicles, which may never be used upon a highway."?

Since Racing Beat is located in Anaheim, CA, we are under the jurisdiction of the California Air Resources Board. Emissions sensitive parts that are offered for sale in California that have not received a CARB exemption must be sold as "racing" parts, which cannot be used upon a public highway. We include this statement with specific product descriptions to inform our customers of the emissions status of that particular product.

Will Racing Beat obtain a CARB exemption for every emission sensitive part that is offered?

No, many of the parts that we offer are intended for racing applications only and it is not possible to obtain an exemption. Selected parts for street applications (i.e. intake kits, street headers, etc…) may be submitted for testing.

Will the addition of an aftermarket part to my car void my Mazda warranty?

This is a question that can only be answered by your local Mazda dealer. We have worked with many Mazda dealers that are "aftermarket friendly" and others that take a hard-line stance towards non-Mazdaspeed aftermarket parts. If your new car warranty is of concern, we suggest you contact your local servicing dealer and speak with their service manager regarding their stance towards an aftermarket part that you are considering.

The aftermarket has been battling this issue for many years. Many products are well-designed and should not adversely affect the performance, drivability, or reliability of a vehicle, but many poorly designed and manufactured parts may indeed have an adverse affect. It is hoped that a "cause and affect" relationship would exist when making a warranty claim determination. For example, the installation of an aftermarket muffler should not have an impact on a warranty claim for trouble with the windshield wipers! However, a broken exhaust hanger or leaking gasket might point to the aftermarket muffler as the source of the trouble.

Do not rely on advertising claims made by a company that states that their part will not impact a warranty - how would they possibly know how your local dealer will address YOUR warranty claim?

Another important consideration is to check your new car warranty for specific exclusions that might apply to your model. For example, for many years Mazda has expressly prohibited the usage of synthetic oil in the rotary engine. If the warranty expressly prohibits the installation or use of a specific product, consider yourself warned and proceed at your own risk!

Important Note: Emission laws vary from state-to-state and are constantly changing. We suggest you contact your local and state authorities for laws and requirements for your specific application. Use this guide as reference only.

Exhaust Sound Level Compliance

Does my exhaust system comply with the law?

All Racing Beat "cat-back" exhaust systems and/or replacement mufflers intended for street use are designed to comply with the California imposed 95-db limit under Society of Automotive Engineers (SAE) test procedure J1169.

However, the addition of performance catalytic converters, headers, presilencers, etc... may impact the sound level of the exhaust system and should be taken into consideration when evaluating the sound levels and tonal quality of a specific exhaust system.

What do I do if I've received a ticket for a "modified exhaust" in California?

Thanks to a SEMA-sponsored law, California automobile hobbyists are now better equipped to fight unfair exhaust noise citations issued by state law enforcement officers. Legislation signed into law in 2002 provides for a statewide exhaust noise testing program that will allow motorists to prove they comply with state noise standards.

The law requires smog check stations that provide referee functions to perform the test. These Referee Stations will issue certificates of compliance for vehicles when tests of their exhaust systems demonstrate that they emit no more than 95-decibels, under Society of Automotive Engineers (SAE) test procedure J1169. Only those vehicles that have received a citation for an exhaust noise violation will be permitted to submit their vehicle for the test. Contact a Referee Station to schedule an appointment.

The law also allows courts to dismiss citations for exhaust systems that have been tested and for which a certificate of compliance has been issued. Fees charged to motorists for the certificates of compliance will pay for the testing program.

"The law forces compliance with an objectively measured standard in a fair and predictable test. Through this procedure, motorists who drive vehicles legally equipped with modified exhaust systems can confirm that they comply with California's exhaust noise standards," said SEMA Director of Government Affairs Steve McDonald. "For years, the enforcement policy used by police officers deemed nearly all exhaust system modifications illegal, even where the noise levels were not excessive or unusual. That policy left exhaust system manufacturers, dealers and their customers without recourse."

In 2001 a prior SEMA-sponsored bill was signed into law that compelled law enforcement officials to tie exhaust system noise citations to the 95-decibel limit and to make clear that aftermarket modified exhaust systems are legal if they comply with the standard. However, exhaust noise citations were still primarily prosecuted solely based on the officer's subjective judgment. This newer law should go far toward improving motorists' odds of beating the ticket in court.

"Motorists who modify their vehicles for durability, appearance and performance prefer aftermarket exhaust systems," McDonald added. "By establishing this evenhanded testing process, this law will serve to benefit consumers who favor these state-of-the-art products, the aftermarket industry which markets them and even police officers who are charged with enforcing the law."

Important Note: Exhaust sound level laws vary from state-to-state and are constantly changing. We suggest you contact your local and state authorities for laws and requirements for your specific application. Use this guide as reference only.

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