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How to Pass the Emissions Test with a Modified Car in California?

As you probably already know, California has some of the strictest emissions regulations in the country. It can be difficult for an ordinary vehicle to pass emissions or smog tests in California, let alone a vehicle that has been either modified or customized.

The following are tips to help you pass your emissions test with a modified vehicle without any problems:

Don’t Forget About Standard Emissions Test Preparations

No matter who you are or what kind of vehicle you have, there are some things you should do to prepare for your emissions test. Any problems you are aware of should be fixed immediately. Make sure your check engine light isn’t on.

If it is on, fix whatever is causing the light to turn on, and be sure to drive your vehicle a bit to allow your car’s computer time to verify that everything is back to working how it should be.

It is also a good idea to have diagnostics ran on your vehicle well before you have your emissions test planned. You can even get a free diagnostic scan at auto parts stores such as AutoParts. Finally, make sure you have kept up on your vehicle’s maintenance.

Have a Reputable Shop

If you’re looking into the top car customization trends right now in Los Angeles, make sure you go to a reputable shop.  A trustworthy professional shop will be knowledgeable about all rules and regulations regarding emission standards in California and how to keep your vehicle in accordance with those regulations.

For example, California’s Health and Safety Code Section 39032.5 defines what constitutes a “gross polluter” and California’s Vehicle Code Section 27156 says that “no person shall operate or leave standing upon a highway a motor vehicle that is a gross polluter”.

The mechanic should be well aware of what will and will not cause you problems down the line legally.

They should also be aware of other laws, statutes, and regulations regarding your vehicle’s customization. For example, some suspension alterations are deemed unsafe in California and are, in turn, illegal.

There are also limitations on how low your vehicle can be. Having expert advice can go a long way.

Buy Locally

Buying your parts locally can help you avoid failing your emissions test. The parts that are illegal and will cause you to fail your emissions test are also illegal to sell. If you purchase parts online from a retailer that is based outside of California, there is a good chance it will not be okay for use here.


Tuning and Turbocharging

If you are wondering if turbos are legal in California, the answer is not usually. Turbochargers and superchargers are almost always considered a modification to the vehicle’s emission control system and deemed illegal.

There are some legal options though. For example, Ford’s Power Pack 2, which can give you an extra 21 horsepower and 24lb-ft peak gains over stock comes with a cold air intake and intake adapter and is completely legal in California as it is in all 50 states.

If on the other hand, you are trying to figure out if tuning is legal in California, it depends. Some tuning does not affect emissions or improves them. Despite this, most tuning refers to a means to enhance the performance of your vehicle while simultaneously decreasing emission control. This is done by overriding the vehicle’s factory engine control unit. This type of tuning will not allow you to pass emission tests.

Executive Order Number

All aftermarket parts have to be certified for use in California or exempt by the California Air Resource Board, also called CARB. In Advisory Number 339 of the California Environmental Protection Agency’s Air Resource Board, they stated that it is required by California State law that all parts installed on your vehicle or engine has an Executive Order Number.

These numbers are engraved on and provided with all aftermarket parts that are okayed for use in California. When you do your emissions test, make sure you have all relevant paperwork to prove the EO number of the parts that are on your vehicle.

Never Alter Original Emissions Control System

Any alterations to your vehicle’s original emissions control system will cause you to fail your emissions test. It is also important to know that your vehicle’s engine must be the same age or newer than the vehicle itself.

This ensures that the emission control system is at the same efficiency as your vehicle’s emission control system was when it left the factory or better.

It is highly recommended to follow all emission control regulations and smog statutes. It can cost you upwards of $5000 per violation found on your vehicle. Not only that, but you will not be street legal or be able to pass your emissions tests otherwise.

Aesthetic Customizations

One of the common car customization myths in California is that all customization and mods will cause you to fail your emissions tests. This is not true. As we have already discussed, there are types of tuning that is completely legal, and there are even turbo kits that have EO numbers and are CARB friendly. Cosmetic customizations such as paint protection film, vinyl wraps, and ceramic coating is absolutely fine.

Of course, there are some modifications that go too far and may be considered a safety hazard. Typically though, cosmetic modifications should not be a cause for concern. For the mechanical modifications that you can’t do, you can make up for it in aesthetic customizations.

Wrapping Up

There are many things you should do before your emissions test to make sure your vehicle passes. These include getting diagnostics ran on your vehicle, fixing existing issues, and making sure you know where to find the best car customization in Los Angeles where they will know what modifications are legal.

Even more important is to avoid any modifications to your emissions control unit and to make sure you have the executive order number for every aftermarket product that has been installed on your vehicle.


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