CAT Delete: Pros, Cons and Cost

Are you looking to increase your horsepower or engine sound by performing a CAT delete? Or are you just looking to save some money on repairs? While it sounds like a great idea to simply remove the catalytic converter, there also several downsides you need to know about.

Whatever your reason for removing the catalytic converter is, this article will help you understand what a CAT delete is and how to do it, how it can affect your car, and how much it costs. Let’s get started!

What Is a Cat Delete?

A cat delete, or catalytic converter delete, is a modification made to a cars exhaust system that completely removes the catalytic converter and instead replaces it with a straight pipe. This can slightly increase the vehicle’s horsepower and acceleration, but also results in increased emissions and may not be legal.

The most common reason someone performs a cat delete on their car is to save money on repairs. The catalytic converter is a wear item that will eventually need to be replaced. By deleting it, the owner of the vehicle can avoid the cost of replacing it.

But it’s not only removed when it’s causing problems. Some people may just be looking for that extra exhaust flow and the beneficial parts of removing a catalytic converter.

Why a Catalytic Converter is Important

Catalytic converters are used to reduce the amount of pollutants in car exhaust. They do this by converting toxic gases into less harmful substances.

A catalytic converter works by using a catalyst, usually a precious metal like platinum or palladium, to convert the pollutants in the vehicle’s exhaust gas into less harmful substances.

The catalyst helps break down and split the toxic molecules into gases that are less harmful to the environment before being released into the air.

The catalytic are extremely important because they help prevent both short-term and long-term health problems like asthma attacks, heart disease, cancer, and premature death.

Removing a catalytic converter is very bad for the environment. Not only does it increase the number of pollutants released into the air, but it also decreases fuel efficiency in most cases, increasing the vehicles’ emissions.

Catalytic converters were first introduced in the 1970s in an effort to reduce pollution from cars. Today, they’re required by law in most states and countries.

How a CAT Delete Can be Beneficial

Despite the fact that most states require the installation of a catalytic converter to drive your car legally, there are several benefits to removing it.

Some people do it for weight reduction, some for the gained horsepower, and some people just because of the improved engine sound we all like.

1. Improved Engine Sound

The biggest benefit of deleting your stock CAT is the improved engine sound.

Most people who get rid of their catalytic converter do it for the improved engine sound, just like a muffler delete.

On big engines, like a V8, the sound is more pronounced. It will have a deep, throaty sound that many people find appealing.

If you’re looking for a way to make your car sound more aggressive without spending a lot of money, then this is one cheap way to do it.

2. Power Gains

Catalytic converters can restrict the flow of exhaust gases, and therefore, deleting them can lead to small power gains.

The catalytic converter looks like a honeycomb which is hindering the exhaust gases from flowing straight out of your exhaust pipe.

By reducing the backpressure, your engine can work more efficiently and make a bit more power.

Of course, the gains are going to be small, and you’re not going to turn your car into a racecar by doing this, but it’s still a nice bonus.

The amount of power you’ll gain depends on the engine and other factors, but it’s usually a small increase.

Without a tune, you could add up to 15 horsepower by deleting the catalytic converter. If you tune your car afterward, you could add up to 30 horsepower.

3. Weight Reduction

Another nice benefit of deleting your catalytic converter is the weight reduction. Catalytic converters are quite heavy, so getting rid of them will save you some weight.

Every ounce lost helps when it comes to performance, and the weight savings can add up if you delete multiple catalytic converters.

On a side note, the weight reduction can also improve fuel economy since your engine won’t have to work as hard to move the car.

4. Low Cost

The cost of deleting your stock catalytic converter is quite low, especially when you compare it to other performance modifications.

You can perform a CAT delete yourself for less than $50 if you have some basic tools and knowledge. If you don’t have the will, expertise, or time to do it yourself, a workshop could help you out.

It’s a very straightforward process that anyone can do, and it doesn’t require any special skills or knowledge.

Downsides of a CAT Delete

Improved sound, small power gains, weight reduction or if your catalytic converter is failing. These are all great reasons to delete your catalytic converter.

But, of course, there are also some downsides to deleting your catalytic converter. The biggest con of a cat delete is the air pollution that it creates, which is illegal in most states and countries.

1. CAT Delete is Illegal

As we mentioned, the main downside of deleting your catalytic converter is that it’s illegal. In most of the US states, it’s against the law to drive without a catalytic converter which could result in a fine if driving without one.

Other countries have similar laws, so it’s important to check the regulations in your area before deleting your catalytic converter.

If you live in a state where a safety inspection is necessary to be able to drive a vehicle, you will definitely fail the exhaust emission inspection.

Not only is driving without a catalytic converter illegal, but it’s also bad for the environment. Catalytic converters help to reduce pollutants and emissions, so getting rid of them will result in more pollution.

If you do decide to delete your catalytic converter, we recommend doing it for track cars only. That way, you won’t risk getting a fine, and it minimizes polluting the environment as it’s not a commuter car that’s being driven every day.

2. Air Pollution

As mentioned, another downside of deleting your catalytic converter is the air pollution that it creates.

Because of the heat the engine produces, it also creates some molecules that don’t normally occur, one of which is carbon monoxide.

Carbon monoxide has the ability to damage the ozonosphere and is also harmful in large doses to humans.

NOx is another pollutant that is created by engines, and it’s also damaging to the environment.

These emissions contribute to acid rain, smog, and health problems such as bronchitis.

Catalytic converters help to reduce such pollutants and emissions, so getting rid of the CAT will result in more pollution.

So while deleting your catalytic converter might be great for performance, it’s not great for the environment.

If you care a tiny bit about the environment, this should be enough to convince you not to delete your catalytic converter.

3. Gas Mileage

Did you know that catalytic converters can also save you money?

That’s right, by reducing the amount of pollutants in your car’s exhaust, catalytic converters can actually improve your gas mileage. And since they last for the life of your vehicle, they’re a great long-term investment.

Although, removing the cat will have a minimal impact on the gas mileage at best. You probably won’t notice the difference.

4. Void Warranty

If your car still has a warranty, deleting the catalytic converter will void it. At least the warranty on the cat itself as well as the rest of the exhaust system.

If you have any problems with your car after deleting the catalytic converter, you won’t be able to get it fixed for free.

We don’t recommend deleting the catalytic converter on a new car unless you don’t care about the warranty.

5. Decreased Resale Price

Another con to keep in mind is that deleting the catalytic converter will likely decrease the resale value of your car.

Unless it’s a car enthusiast who’s buying the car, most people prefer cars that are legal and won’t get them into trouble.

If you’re not going to keep your vehicle until it’s last breath, deleting the catalytic converter might not be the best idea.

6. Tuning is Needed

If you delete your catalytic converter, you’ll also need to retune your engine.

Related: P0420 Code – Meaning, Causes, Symptoms, & Fixes

That’s because the catalytic converter helps to maintain the backpressure inside of the exhaust system.

Without it, the backpressure will be too low, and the engine won’t run as efficiently.

The car’s ECU (computer) needs to be re-programmed to adjust the air to fuel ratio and timing.

If you don’t tune the engine after deleting the catalytic converter, you’ll likely experience a decrease in performance.

The check engine light could even illuminate on some cars, as removing the CAT lets the toxic gasses pass through the exhaust system making the sensors warn the car about the “broken” catalytic converter that’s missing.

Catalytic Converter Delete Cost

How much does it cost to delete the catalytic converter?

The price will vary depending on the make and model of your car as well as the shop you visit. On average, you can expect to pay between $200 and $500 to have the catalytic converter deleted, not including the tune required. Removing the CAT yourself could cost as much as $50 for the materials needed.

The only cost of doing it yourself is the cost of a replacement straight pipe that is welded to where the CAT used to be located.

Therefore it’s quite a simple job to do even at home if you’re somewhat familiar with cars and welding.

How to Delete a CAT At Home

To perform a CAT delete at home, you need the following tools:

  • A welder
  • A hacksaw or reciprocating saw (a grinder could work)
  • A replacement pipe (can be bought at any auto parts store)
  • A friend (Not necessary, but benificial, to help you hold things in place while you weld)

Here’s how to perform a CAT delete at home:

  1. Find a pipe extension that’s the same diameter as the exhaust system. The pipe is required to replace the catalytic converter. Make sure the inner and outer diameter matches the car’s exhaust system’s diameter.
  2. Jack up your car to access the exhaust system. Use jack stands to secure the car as you will be working underneath.
  3. Dismount the exhaust system. It’s easier to weld an exhaust system that’s not attached to the car.
  4. The next step is to find the catalytic converter on your car. It’s usually located right after the exhaust manifold and before the resonator and muffler.
  5. Once you’ve located it, use the hacksaw or reciprocating saw to cut it out. Be careful not to damage any other parts of the exhaust system while you’re doing this. Some vehicles use clamps and bolts instead of welding their CAT in place.
  6. Next, take the replacement pipe and weld it in place of the catalytic converter. Make sure it’s welded securely, ensuring there are no leaks.
  7. Finally, have your friend help you start the car and make sure there are no leaks in the exhaust system. If everything sounds good, you’re all set!
  8. Don’t throw out the catalytic converter. The cat delete is irreversible, so don’t toss that expensive catalytic converter if you want to reverse the CAT delete.

Here’s a great video by Salim Karimov, visually showing you how to do a CAT delete yourself.


Deleting the catalytic converter is a pretty straightforward process, but it’s important to keep in mind that you’ll need to retune your engine afterward.

The cost of doing it yourself is the cost of a replacement pipe, which should be welded in place of the old catalytic converter.

We don’t support performing a CAT delete on daily drivers due to the air pollution emitted by the car. We only recommend doing it on track cars that will be properly tuned afterward.

There are a few benefits of doing a CAT delete, but the downsides do not outweigh the pros, in our opinion. We do not recommend doing a CAT delete on your car.

Photo of author

Robin Söder

Robin has always been passionate about cars ever since young age. Over the years, Robin has worked on thousands of cars and gained invaluable experience in the process. He is considered an expert in his field and is often consulted by other mechanics for advice.

1 thought on “CAT Delete: Pros, Cons and Cost”

  1. Thanks for the info Robin, after reading this I,ve decided on installing a new cat instead of deleting the old one. Fuel economy has always been an important issue for me as I,m on a rural property and the nearest town is 45 miles away. And the idea of Not polluting is atractive as well .So thanks again for the info ,have a good drive.


Leave a Comment