Federal vs. California Emissions: What You Need to Know

If you don’t live in California, you might think that the state’s emissions regulations have nothing to do with you and your car. But in reality, many vehicles sold throughout the country come with emissions systems designed to meet California’s standards. Furthermore, many states outside of California now adhere to the emissions requirements established by the California Air Resources Board (CARB).

If you want to select the right replacement part for your vehicle—and also stay on the right side of the law—it’s important to understand the differences in the requirements set forth by the Environmental Protection Agency (EPA) and CARB.

What’s the Difference Between Federal and California Emissions Standards?

Simply put, California emissions standards are much stricter than those implemented by the EPA. The EPA is a federal government agency that oversees environmental protection matters.

In 1970, congress passed the Clean Air Act (CAA). The law gives the EPA the authority to set nationwide vehicle emissions standards. But under one section of the act, California was granted the ability to seek a waiver from federal standards, thereby allowing the state to set its own stricter regulations. Other states can also adopt California’s more stringent emissions standards.

Although the waiver system was upended in 2019 due to shifts in government policy, it was reinstated in 2022.

Is Your Car Built to Federal or California Emissions Standards?

A car can come from the factory with either a federal or California emissions package. The primary difference between the two configurations is the catalytic converter. Generally, a converter designed to meet California’s requirements contains more of the precious metals needed to reduce tailpipe emissions.

And guess what? Your car doesn’t need to have been originally sold in the Golden State to have California emissions equipment. Because California is such a huge market, many automakers choose to make just one version (the California emissions version) of a particular model and sell it nationwide. Even if you buy a brand-new vehicle in Ohio, there’s a good chance it will come with California emissions equipment.

At this point, you might be wondering how you can tell whether your car was built to federal or California standards. To find the answer, all you need to do is check the emissions systems decal located under the hood.

If a vehicle has a California-compliant system, the emissions decal will say that the vehicle conforms with both EPA and California regulations. The image above is an example of an underhood decal on a car built to California emissions standards.

On the other hand, a vehicle built to Federal emissions standards will not list California anywhere on the emissions decal. Instead, the decal will just note that the vehicle complies with EPA (federal) emissions standards. The image above is an example of an underhood decal on a car built to Federal emissions standards.

Do You Live in a CARB-Compliant State?

As was mentioned, previsions within the CAA allow other states to adopt California’s emissions standards. These so-called CARB-compliant states currently include:

• Colorado
• Connecticut
• Delaware
• Maine
• Maryland
• New Jersey
• New Mexico
• New York
• Nevada
• Oregon
• Pennsylvania
• Rhode Island
• Virginia
• Vermont
• Washington
• The District of Columbia has also adopted the standards

Catalytic converters and other emissions-related parts that are not CARB-approved cannot be sold in (or shipped to) the states of California, Colorado, New York, or Maine.

Can You Install Federal Emissions Parts on a California Emissions Vehicle?

If you have a California emissions vehicle, you should always install CARB-approved replacement parts (where applicable) to adhere to government regulations. Getting the right part will also help ensure your vehicle operates as designed and passes emissions testing (if required in your area).

Also, if you modify your car in a way that might affect tailpipe emissions, you’ll want to ensure the modifications comply with state and local regulations in your area. Otherwise, your car might not pass emissions testing, and you could even incur a penalty in some cases.

Note: Some rules and regulations are subject to occasional change. Be sure to check the current emissions requirements in your state.

Where to Get CARB-Approved Parts for Your Vehicle

Whether you’re living in California or have plans to visit the state for a few weeks, it’s a good idea to find CARB-approved parts for your vehicle. Not only will they help you avoid penalties, but they also give you a way to reduce your ride’s emissions. Struggling to find such parts? We have you covered here at CarParts.com.

Whether you’re in the market for a catalytic converter or an exhaust gas recirculation valve, you can find CARB-approved variants in our catalog with just a few clicks. Our vehicle selector takes the guesswork out of finding parts that fit, while our filters pinpoint the products that comply with the emissions standards.

We source our products from highly trusted and touted manufacturers, so you know you’re getting your money’s worth if you order from us. In addition, we have a 60-day return policy in the unlikely event you’re not satisfied with the product you ordered.

Shop now at CarParts.com and relieve yourself of the worry of future emission tests.