Can You Drive Without A Catalytic Converter?

Is it OK to drive without a catalytic converter? Can the car even run without one and is it safe? Here's the ultimate guide.

The catalytic converter hinders toxic gases produced by the engine from getting released into the environment.

It is possible to drive without a catalytic converter, however, there may be a few things you should consider if you plan to opt-out of a catalytic converter.

A few things to consider include the legality of removing the catalytic converter, warranty, comfort, and more.

To answer the question, “can you drive without a catalytic converter” the simple answer is yes, you can, but it is illegal.

Unfortunately, catalytic converters are a target for many thieves as they contain precious metals such as palladium and platinum that are necessary for the operation of the catalytic converter.

If you have fallen victim to a catalytic converter theft, don’t worry! We will also cover what to do if your catalytic converter has been stolen.

Below, we will cover everything about removed catalytic converters, regardless of whether they are intentionally removed or not.

Let’s get into it!

Table of ContentsShow

Driving Without A Catalytic Converter

catalytic converter replacement and repair cost

Your car can drive without a catalytic converter as it is not essential for it to run, however, it can impact a few aspects of driving the car.

The first thing that perhaps is not very noticeable is that toxic gases will be expelled into the environment, which is not good in any way.

More noticeable aspects of a removed catalytic converter include a louder exhaust sound, drone, and, most likely, a check engine light.

While the latter can be dealt with in various ways, a louder exhaust sound and drone are harder to deal with.

Most people that remove their catalytic converter do so to have a louder exhaust and a sportier feeling, however, in most cases, that comes with a so-called drone.

Simply put, drone is involuntary vibrations felt in the cabin when driving as the engine and exhaust vibrate at different frequencies.

Is It Illegal To Remove The Catalytic Converter?

Police Officer Writing A Ticket On Duty

Under the Clean Air Act, it is a federal offense to remove or even tamper with the catalytic converter unless specific conditions are met.

This means it is always illegal to remove the catalytic converter to gain an extra few horsepower or get a more aggressive or sportier sound.

Replacing The Catalytic Converter

Replacing a catalytic converter is also strictly regulated and can only be done if there is a legitimate need for a replacement.

A legitimate need for a replacement may be if the original catalytic converter is broken or the car does not pass an emission test.

catalytic converter repair

Even if there is a legitimate reason to replace a catalytic converter, further conditions must be met with the replacement.

For example, the new catalytic converter must be the same type as the original one, and the model of the catalytic converter must be in accordance with the car manufacturer’s specifications.

It does not stop there. The replacement must be appropriately documented, regardless if you replace it yourself or a shop does it for you.

The abovementioned rules are federal laws, but each state may have additional laws that may require additional steps to replace a catalytic converter.

For example, the state of California requires the catalytic converter to be CARB-compliant to satisfy the more rigorous air pollution regulations in California.

Catalytic Converter Stolen, What Should I Do?

Stolen Car Parts

Unfortunately, the catalytic converter contains precious metals and is therefore subject to getting stolen by thieves that want to earn a quick buck.

Some car models have a greater amount of precious metals, making them more prone to get their catalytic converter stolen.

A risk factor to getting your catalytic converter stolen is if you own a car that has a high ride height which, consequently, makes it easier to remove the catalytic converter without having to lift the car.

If the unfortunate has happened and your catalytic converter is missing, you should immediately contact your local authorities and file a report.

More often than not, thieves do not stop at one vehicle but have most probably stolen a few catalytic converters in the area.

After you have reported the incident to your local authorities, contact your insurance company to see if your insurance will cover the cost of a catalytic converter replacement.

When you have taken the steps above, you may replace the catalytic converter at a reputable shop. Make sure that all the conditions mentioned previously in the article are met.

Prevent Getting Your Catalytic Converter Stolen

what is inside a catalytic converter

If there have been a lot of thieves stealing catalytic converters in your area recently, or you drive a car that is more prone to get the catalytic converter stolen, there are a few steps you can take.

The first step to protect against potential theft is to mark your catalytic converter with a property marking system, making it tough for thieves to sell it further.

There also exist guards for catalytic converters that make it substantially harder for the catalytic converter to get stolen.

If you have access to a garage, it is always recommended to park the car inside as it both protects it from theft and also from harmful environmental factors.

Removing The Catalytic Converter

Catalytic Converter

Even though it is illegal, and we strongly recommend not removing the catalytic converter for an illegal reason, you may still decide to do so.

If you do, it may not be as simple as removing the catalytic converter and replacing it with a straight pipe. In almost all instances, a tune must be done to accommodate the new system.

The price of a tune will differ depending on the shop, but it will cost a few hundred bucks just for the tune.

In some cases, the check engine light can be removed by ECU tuning. Others use O2 extenders that move the downstream sensor further from its original position to trick the ECU.

Is It Safe To Drive Without A Catalytic Converter?

Driving car

It is perfectly safe to drive without a catalytic converter, however, unless your car has been tuned for your specific setup, you will most probably have a few minor problems.

These problems include a check engine light, loud exhaust, drone (as previously explained), higher fuel consumption, and more.


You can drive without a catalytic converter as it does not harm the engine but keep in mind that it is illegal to drive without a catalytic converter in every state.

Most people that delete their catalytic converter do so to either gain a few horsepower, a louder exhaust, or both.

Sometimes, the catalytic converter gets bad and is due for a replacement.

catalytic converter

Keep in mind that a catalytic converter rarely goes bad by itself. Instead, there is an underlying problem that should be diagnosed and fixed.

As the catalytic converter contains precious metals such as palladium, rhodium, and platinum, they are a valuable target for thieves, which steal and then sell them for a good profit.

Hybrid cars and vehicles with high clearance, such as trucks and SUVs, are most commonly affected by catalytic converter theft.

According to the law, you may only remove the catalytic converter if it is going to be replaced, but several conditions must be met to replace a catalytic converter.

For example, you may only replace a catalytic converter if there is a legitimate reason, such as the original not working properly.

When replacing a catalytic converter, further conditions must be met in the process, including documenting the replacement.

You should also be aware of your state’s legislation regarding catalytic converters, as some states, such as California, require CARB-compliant catalytic converters.

If you decide to remove the catalytic converter, despite it being illegal, it is not as simple as removing it and replacing it with a pipe, as you will get a check engine light and other problems.

When taking everything into consideration, the best thing would be to keep the catalytic converter and only replace it if it does not work properly.

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Bajro Muric

Bajro is an ASE-certified master technician and car enthusiast with a love for writing and teaching. He writes about anything regarding cars, from common problems and fixes to racing.