Can I Replace My Catalytic Converter With a Straight Pipe?

If you have just had your catalytic converter stolen or damaged, you may wonder if you can replace it with a straight pipe due to the high repair and replacement cost.

The simple answer is yes! You can replace your vehicle’s catalytic converter with a straight pipe.

The catalytic converter forms a part of the exhaust system that helps to reduce the harmful substances in the exhaust gases. Many people are replacing catalytic converter with straight pipes because of the promised extra horsepower, better engine breathing, or improved sound.

Replacing catalytic converter with a straight pipeis not just limited to removing the catalytic converter alone. It may involve removing the muffler and reprogramming the computer system.

This article will discuss can I replace my catalytic converter with a straight pipe and how to remove catalytic converter and replace with straight pipe. Additionally, I will discuss the implications of replacing the catalytic converter with a straight pipe.

replacing catalytic converter with straight pipe

Can I replace my catalytic converter with a straight pipe?

A straight pipe can replace the catalytic converter. This is a great way to increase the exhaust flow and reduce restriction. It is also reported to improve engine power output and the vehicle’s sound but it is illegal.

The straight pipes run from the cylinder head, connect with one or two pipes and lead out the exhaust tips. With a straight pipe, the catalytic converter that comes with the vehicle is completely taken out and replaced with a pipe that leads straight to the exhaust tip from the engine.

Furthermore, after-market straight-pipe often eliminates the muffler and the catalytic converter to create a straight path for the gases to pass through from the engine. This modification allows gasses to be expelled faster and the engine to breathe better, creating more power and torque.

The catalytic converter plays a significant role in the exhaust system. It ensures that the amount of harmful gasses the vehicle releases through the exhaust system is reduced significantly. It helps save the environment from toxic gasses and complies with the state’s rules. 

In addition, the legality of removing the catalytic converter and replacing it with a straight pipe is questionable. Straight pipes are not illegal on their own. However, it becomes unlawful when the vehicle exceeds the required sound limit and emissions levels.

It is important that before you modify your vehicle’s exhaust system to a straight pipe, you make inquiries about what the state laws are saying about the modification. Note that there is no part of the United States where the straight pipe is legal.

How to replace a catalytic converter with a straight pipe

If you are considering replacing the catalytic converter, ensure the modification can provide what you expect for your vehicle.

Below is how to replace catalytic converterwith a straight pipe.

Step 1

Find a safe place where you can work on your vehicle. Park the car and raise it using a hydraulic jack. Place a jack stand at every corner of the vehicle’s frame. Once the stand is properly placed, lower the jack and check that the car is properly supported by the jack stand.

Step 2

Allow the hot exhaust system to cool down if the vehicle has been driven not too long ago; the catalytic converter can be extremely hot in such conditions.

Step 3

Get under the vehicle and spray penetrating fluid on the mounting bolts holding the catalytic converter. Proceed to use a saw to cut open the flanges and measure the part that you will be installing the straight pipe.

Once you are done measuring, cut the Cat completely from the exhaust pipe.

Step 4

Lower the catalytic converter to the ground slowly. Please do not throw away the catalytic converter; retain it for the future.

Step 5

Get the straight pipe you will be using, and ensure it is the right size for the space created by the removed Cat. Weld or braze the new pipe to the exhaust.

Step 6

Bolt the new pipe in place using the original mounting bolts and tighten with the wrench in a clockwise position. 

Step 7

Raise the vehicle using the hydraulic jack and then remove the jack stands. Lower the hydraulic jack until the car rests properly on the ground, then remove the jack.

Will removing catalytic converter harm engine?

Removing a catalytic converter from a vehicle will not cause any damage to the engine. Although the catalytic converter is an important part of the exhaust system, removing the part will not affect the engine performance.

The catalytic converter has the function of reducing the harmful substances in exhaust gasses. In most cases, catalytic converters create back pressure if improperly maintained, affecting the engine’s efficiency.

Once the catalytic converters get restrictive after some time of use, it causes exhaust gas flow to slow down, which could drop the engine output. It is one of the reasons why people opt for cat delete or straight pipe.

With a straight pipe, you will not likely face any restrictions in exhaust flow. The gas flows freely from the engine to the exhaust tip without any components in the system that may perform any form of purification that may slow down the gas.

Does removing catalytic converter increase speed?

Removing the catalytic converter will increase the speed at which gases flow through the exhaust system. Back pressure will reduce when this happens, which could improve the engine’s performance.

The catalytic converter can create an extent of back pressure, which could affect the engine’s power output. Once the catalytic converter is removed, gas flow from the engine is no longer restricted. The exhaust gas can leave the exhaust system faster, allowing the engine to create more power.

Removing the catalytic converter and installing a straight pipe will help your engine gain 5 to 10 horsepower. The increase in output is not that significant, which does not make it an ideal modification if you are looking for more horsepower for your vehicle.

The increase in horsepower through Cat delete might not be noticeable when driving. You may not be able to notice extra speed when driving, but there will be better engine performance.  However, the modification is a good option for sound improvement.  


Before you replace catalytic converter with straight pipe, first determine what you want to achieve from the modification. If you want more horsepower for your vehicle, there may be better modifications than a straight pipe. The reason is that a straight pipe adds little horsepower. However, if you want to improve the vehicle’s sound, the straight pipe could be the one for your car.

Akindayini Temiloluwa

I am Akindayini Temiloluwa, an automotive expert writer and car enthusiast. I have over three years of experience in the automotive writing niche and have completed over 300 pieces of content from 50 projects. I have vast knowledge and skill in vehicle repairing, all mechanical work, car upgrades and maintenance. My goal as an automotive content writer is to simplify the most challenging concepts for my readers, help them self-diagnose what may be wrong with their vehicles and offer real value for their time.

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