How to cut off a Catalytic Converter?

The catalytic converter is an essential component of your car’s emission system that helps save the environment from harmful emissions. Its duty is to convert toxic gasses produced by the engine into eco-friendly fumes. However, over time, the cat can get damaged, or its precious metals responsible for reducing harmful gasses can get coated.

When this happens, the cat will no longer function effectively. Hence, the need for cleaning or outright replacement. However, to clean or replace the cat, one must remove it from its compartment. So, in this article, I will be showing you a step-by-step guide on how to cut off a catalytic converter properly.

how to cut off a catalytic converter

How to cut off a catalytic converter – Step-by-step guide

The catalytic converter, no doubt, can, over time, get dirty or even damaged. A faulty cat will result in strange engine noises, especially when accelerating, and even cause the engine check light to come on. Hence the need to take it off to clean or replace it.

Generally, having an expert remove your cat will save you stress and time and make the job neat; but this will cost you some cash. To minimize cost, you can do this yourself if you have the right catalytic converter removal tools and knowledge.

Tools needed

  • Vehicle jack and jack stands
  • Wheel chocks or any strong wood
  • Lubricating oil
  • Set of sockets or wrench
  • Oxygen sensor socket
  • Sawzall, reciprocating saw, handheld grinder, chain pipe, or any metal cutting tool


1. Prepare your car

Park your car on a solid flat surface. I have always hit on this point, as parking on a solid surface will prevent the issue of vehicles sinking when working.

2. Jack up your car

To access the cat, always jack up the car totally from the ground and support it with jack stands and wheel chocks. While the stands will act as a support in case the jack fails, the chocks will prevent the tires from rolling.

3. Let the exhaust cool

I usually take this step seriously as the first two steps because I don’t want to get burnt or injured. Always allow the car’s exhaust to cool to avoid burns. Also, wear gloves to feel the exhaust with your hands. If it’s still hot, wait for some time.

4. Locate the catalytic converter

Now, slide underneath the vehicle and locate the catalytic converter. Depending on your car model, the cat is situated at the center of the exhaust. Many catalytic converters are connected to the exhaust pipe via bolts. But if you have already replaced yours, it’s likely welded or clamped to the exhaust.

5. Remove the Oxegen (O2) sensors

Most cats have oxygen sensors in them. This sensor helps measure the air left in the exhaust to balance the air-fuel ratio needed for proper combustion. So if your cat has the O2 sensor, remove them from the cat and keep them aside. Otherwise, move to the next step.

6. Lubricate corroded or rusted bolts

To make it easier to remove the bolts for bolted cats, always pour in lubrication oil to soften jammed and rusted bolts. Then let the oil sit for at least 10 minutes before removing the bolts.

7. Detach the cat by unscrewing the bolts or cutting out the cat

Now remove the bolts starting from the rear bolts—the one closest to the opening end of the exhaust. I use a socket if the bolts on the rear end of the cat are loose and a wrench if secured tightly.

If you have a built-in cat—that is, the one welded to the exhaust, cut the cat away from the exhaust from both connecting points. To do this, I often use a sawzall to cut both ends of the tube following the existing lines. Unless you are confident on how to cut catalytic converter off with a sawzall or any metal cutting tool, take it to a repair shop.

how to cut off a catalytic converter



What is the best tool to cut off a catalytic converter?

There are many catalytic converter cutters that come useful in cutting off a cat, and which is the best depends on your preference. Generally, a Sawzall, reciprocating saw, and even a grinder come in handy, but a chain pipe cutter falls into the category of the best tool to cut catalytic converter, as it helps cut through where most cat cutter tools can’t get through.

Can I cut off my catalytic converter?

You can cut off your catalytic converter yourself. However, how simple or hard this is will depend on your vehicle’s age or design. If your catalytic converter is held to the exhaust via bolts, the process is a bit simple. All you need is to remove the bolts or clamps from both ends of the cat and remove the cat from its slot. 

If, however, yours is welded to the exhaust system, you would need to cut the cat’s tube with a torch or any metal cutting tools. The welded ones are always tedious to remove, so if you don’t know your way around, contact your mechanic. As other exhaust components also stand the risk of damage which can lead to exhaust leaks if anything goes south.

Ensure you replace the cat, as it is illegal to drive in most states without it. Aside from being illegal, driving without a cat will cause the check engine light to turn on and off and may cause your car to enter into limp mode. So you may want to learn how to remove catalytic converter without the check engine light coming off and on.

How do thieves remove catalytic converters so fast?

Cars with high ground clearance make it easier for thieves to steal cats. Here they won’t need a jack to even raise the vehicle. All they need is to slide under the vehicle and cut the cat out from the exhaust pipes using any metal cutting tool.

The quickest way to cut off a catalytic converter is by unscrewing the bolts. So if the cat is bolted to the exhaust, all they need is to lose the bolts and take out the cat. The none usefulness of a jack for high clearance cars makes it faster and can take a professional thief less than five minutes to do this, especially for bolted cats.

Worse is if the thief happens to be a professional mechanic who specializes in cat removal. As the process becomes easier. These set of thieves know how to cut catalytic converters off quietly in the shortest time

Can you cut the catalytic converter with a grinder?

Yes, you can cut a cat using a grinder, though using it with a cut-off wheel is a better option. All you need to do is cut both ends of the exhaust pipes the cat is attached to.

Using these tools requires some expertise. So if you don’t know how to use them, contact a professional. You can get a list of shops specializing in cat removal by searching catalytic converter removal near me.

Will my car run better if I remove the catalytic converter?

Your car will run better without a cat. Generally, while a cat helps minimize toxic gases released by your engine, it also restricts airflow. So with the cat out, exhaust fumes will quickly leave the engine allowing the engine to breathe in more air faster. Invariably, resulting in better throttle response, increased torque, and horsepower gain.

However, this will cause the release of toxic gasses into the atmosphere since the cat, which is supposed to minimize this, is no longer there. Moreover, a catless car will result in you failing emission tests. Again, most recent vehicle cats have sensors around them.

These sensors help monitor the air left in the exhaust, which helps balance the air-fuel mixture needed for proper combustion. Cutting off the cat means taking off the sensor as well. Without these sensors, the engine will not get the appropriate air and fuel required to operate, causing the engine to function incorrectly.

How does a car sound without a catalytic converter?

A car without a catalytic converter will sound louder. Usually, the presence of the cat reduces the amount of gasses and sounds. A catless vehicle, however, will allow the unrestricted flow of noise, making the car exhaust louder but causing air pollution.

Most car Athletes who have a thing for car sound are fond of doing this. If you want louder sound and increase in horsepower, delete the cat con. This means you should replace the cat con with a straight pipe. By doing so, the engine pressure will be reduced, allowing the free flow of gas and noise.

So, while your car will sound louder, engine performance will also improve. However, you would need to reprogram your engine’s computer to enable you to adjust the oxygen level to prevent the check light coming off and on. For this reason, learning how to remove the catalytic converter and replace it with a straight pipe is vital.

Final Words

Knowing how to cut off a catalytic converter is a simple way of minimizing cost when there is a need to remove the cat. Depending on your vehicle’s age and model, you can remove the cat by removing the clamps (for bolted cats) or cutting it out (for welded cats).

Understand that it is criminal to drive without a cat in most places in the US as it can cause air pollution. So ensure you replace the cat with a similar one to complete the exhaust system.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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