Know Your Rights – Are my car mods legal?

Know Your Rights – Are my car mods legal?


Owning a modified car has definitely becoming an increasingly difficult feat in recent years. When you modify your vehicle or customize it, chances are you’ve been pulled over and given a fix it ticket at some point. If you don’t know what makes your car mods legal, this primer can help you understand your rights. To make things worse the EPA seems to be targeting car enthusiasts and race cars in general with their new proposal to ban race car conversions.

Legislation and new laws are blurring the lines and making it harder to understand just what make your car mods legal. Being pulled over for an exhaust that’s too loud, your car being too low or any other infraction is never a good time. If you’ve gotten a fix it ticket or infraction recently, you can benefit from this article to show you what your rights are.

Is my Engine Swap legal?

Engine swaps are one of the biggest advantages to owning an import performance vehicle. The abundance of JDM engines that can easily be swapped into your car can give your car a new lease on life. Finding the best JDM swap is easy compared to figuring out the legality of engine swap.

When it comes to engine swaps, it’s certainly one of the upgrades that should be researched. If you are planning on modifying your car and want to know what makes your car mods legal, you should stick to a engine swap that’s available in the US. Swapping in an engine that’s not available domestically can lead to issues. More specifically the document from the EPA called the “Engine Switching Fact Sheet” outlines this information.

K Series Swap 2

Depending on what state you live in, there are legal measures you can take to legalize your engine swap.

These involve certifying your swapped engine, to ensure that it meets or conforms to your local state emissions.

The EPA deems that any engine swap is illegal when it’s an engine that does not meet this criteria. The specific language behind the legislation refers to any engine swap that “will not consider any modification to a certified configuration to be a violation of federal law if there is a reasonable basis for knowing that emissions are not adversely affected.”

Headline for Top Ten Honda Engine Swap Tips
John Huh John Huh
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Top Ten Honda Engine Swap Tips

Building a Honda swap isn't quite as popular as it used to be, but it's still an excellent bang for the buck option when planned right. When you build a Honda engine swap, the massive selection of aftermarket parts is the built in competitive edge. Sharing the same chassis can provide multiple benefits including use of factory mounts and parts when getting your Honda engine swap done.

If you need to plan a engine swap, learning what Honda swap parts and mounts you need is vital. When working on your project, make sure to check the top ten Honda engine swap tips for some important pointers to get your Honda back on the road where it belongs.


Remove your TPS

Apr 22, 2015
Remove your TPS

Do yourself a favor when remove the throttle position sensor (TPS) when you are removing your engine or installing your donor engine. Many times when raising or lowering your engine into or out of your chassis, this sensor can break or become damaged.

This can be especially true for JDM engines that have been shipped halfway around the world, usually by people who could care less what happens to some sensor.

Remove TPS or Throttle Body -

Skip the drama and simply remove your TPS ahead of time. You will need to recalibrate the TPS upon reinstallation, so if you don't have a multimeter handy, remove your throttle body instead. If you are swapping a B series engine into your Honda, take a look at our B series TPS service guide. This guide contains the B series TPS wiring diagram you need to service and calibrate your throttle body.

This sensor can become another cost and repair that you Honda engine swap project didn't need. Don't let this happen to you and remove this sensor before it can become damaged. Of course you can always save time by simply picking up a BlackWorks TPS sensor, or a replacement BLOX TPS sensor to save time in your B series swap.

The process behind legalizing your engine swap is known in California as the BAR inspection. There are a few rules to swapping in an engine, and you don’t necessarily need to swap an engine from the same manufacturer. The important key to remember is that your emissions equipment matches the swapped engine in question, and that your vehicle will pass the required emissions standards and tests.

Are my Exhaust car mods legal?

Upgrading your exhaust system can be a great way to increase your horsepower and torque. Parts like an aftermarket header system can elevate your engine performance. Unfortunately an upgraded exhaust is also one of the most common reasons for you to be pulled over.

But that doesn’t mean that you should stop modifying your car. The fact is that performance modifications regarding your exhaust are perfectly legal in the eyes of the EPA, as long as they don’t change your emissions equipment. State laws vary however regarding exhaust upgrades, and if you are wondering if your exhaust system is breaking any laws check out this article here.

Headline for Most Popular Engine Modifications
John Huh John Huh
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Most Popular Engine Modifications

Hopping up your car has been one of the oldest hobbies for auto enthusiasts. People are always happy with their new car for the first few weeks, but it's only a matter of time before many people are bit with the "mod bug" and want to learn how to make your car faster. Installing engine mods has been a popular pastime for many auto enthusiasts, giving people a fun way to tinker and tweak their cars. Whether your goal is to increase horsepower or to improve fuel economy, there are many engine mods that can help you get the job done.

The engine in your car, truck or van works on four steps or a four cycle combustion process. The engine crankshaft spins your rotating assembly of pistons and rods. As your pistons move down the combustion chamber, it draws in air from your intake through your intake valves. When your engine pistons move back upwards, it pressurizes the atmospheric pressure and your injectors deliver an atomized spray of fuel. Your engine computer then ignites the air fuel mixture to create kinetic energy.

This kinetic combustion of energy is what creates horsepower and drives the crankshaft back around as the process is repeated. If you are interested in learning some of the most popular ways to increase your horsepower, here are some of the best engine mods for your car below.


Air Intake Engine mods

Jan 21, 2016
Air Intake Engine mods

Your engine basically acts like a giant air pump, so the best engine mods will always be about moving more air in and out of your engine. Air Intake kits can bolt right up to your throttle body, allowing you to easily increase air flow to your engine in the most efficient manner possible. There are several ways to increase air flow and they generally revolve around these important points about your engine intake.

  • More Air flow - Your stock air intake system is restrictive and made to operate quietly to minimize engine noise. Install a high flow intake filter, or a intake kit to deliver air faster and increase air flow to your engine.
  • Colder Air - The colder your intake air charge, the more dense it becomes which makes for more horsepower generating potential. When your intake temperatures are warmer the conditions for your engine to run efficiently is less than ideal. Cold air intake kits relocate your air filter to a colder area, usually outside of your engine bay or by using a air intake heat shield. Install a cold air intake kit to lower your air temperature and your engine will love you for it!

For most state legislation and exhaust laws however, SEMA’s established standard of 95dB is the guideline. This maximum sound output rating is used for most sport compact applications, and adhered to by aftermarket exhaust manufacturers. If this sounds confusing here’s a quick rundown of exhaust legality facts if you are wondering what makes your car mods legal.

  • Exhaust must remain similar to factory exhaust
  • Exhaust system must not exceed 95dB
  • Emissions equipment – Catalytic converter must remain intact


These requirements to what makes your car mods legal fall in line with emissions bill AB2289, enacted on January 1, 2013.

Known as California Gold STAR Stations these smog facilities changed the way OBDII vehicles are to be tested.

For more information check our article here on the new OBDII testing procedures. Of course if your car has been chosen for a STAR station test, chances are you will need to go back to stock before you can pass your next emissions test.


How low is too low?

One of the more frustrating fix it tickets you could ever receive is for ground clearance. This is also known as Section 24008 of the California Vehicle Code. This deals with the clearance of your vehicle, and it stipulates that no part of your vehicle can be lower to the ground than the distance between the bottom of your rim.

If that’s not enough there’s also Section 24400 of the California Vehicle Code that states the middle of a vehicle’s headlight cannot be lower than 22 inches from the ground. If you’ve recently gotten a ticket for being too low, it’s a situation that can be remedied through the use of adjustable coilovers.

In many other states outside of California however, this is purely a judgement call. If you live in a state that does not have these specific requirements to how low your car can go, it’s up to the officer to decide. Your suspension isn’t one that most people think about when considering what makes your car mods legal, but it’s an important factor.

Are my HID car mods legal?

High Intensity Discharge or HID light conversion kits were all the rage a few years ago, and today they are cheaper and easier than ever to install. However that doesn’t make all HID car mods legal. In fact according to the Federal Motor Vehicle Safety Standard (FMVSS) Number 108, most HID kits are in fact not legal for street use.

car mods legal 4When it comes to your headlights, there’s two different kinds of housings. Most OEM headlights use a reflective style of housing, meant to scatter light efficiently to illuminate the road ahead.

Most people simply slap in a HID kit into their vehicle with reflective halogen style headlight housings. This not only creates a dangerous driving condition by blinding oncoming traffic but it actually decreases your visibility. That’s because the HID kit you are installing is meant for a projector style of headlight, which carefully aims the beam for optimum performance.

If you’ve haphazardly installed just the basic HID kit into your vehicle, chances are your HID car mod is not legal. Make the change to a projector style headlamp or convert to HID properly to make sure that your HID car mods legal.

Know Your Rights

If you have been handed a fixit ticket by your local peace officer, it’s no time to panic. Use this time to educate yourself to your rights to make sure that your car mods legal. Understand the infraction that you’ve been given to fight back legally, and to prove without a doubt that your car mods legal and well within the law.

However there is a wind of change both on the federal level and the state level when it comes to aftermarket performance. Fact is that automotive enthusiasts are becoming an endangered species as laws continue to crack down on our favorite pastime. Recent proposals from the EPA as well as changes to state laws are making it harder than ever to modify your car legally.

You can take a stand and fight back. Check out the SEMA website for enthusiasts at to join the SEMA Action Network. This gives you free access to all of the latest in federal and state motor vehicle code, and keeps your car mods legal by informing you of any change or updates to the law. Doing your part enables the SEMA Action Network to work on behalf of all car enthusiasts everywhere and fight for our rights to modify and enjoy our vehicles.