How To Replace Catalytic Converter Without Welding – Ultimate Guide

A catalytic converter is an essential component of a vehicle’s exhaust system, responsible for reducing harmful emissions that result from the combustion process. Over time, catalytic converters can become clogged or damaged, leading to decreased engine performance and increased emissions.

While traditionally replacing a catalytic converter involved welding, there are now options available for those who want to replace their catalytic converter without welding.

In this guide, we will explore the steps involved in Replace Catalytic Converter Without Welding, as well as the tools and materials needed to complete the job successfully. With the right preparation and approach, anyone can replace catalytic converter without welding and get their vehicle running smoothly again.

How Does it Work?

Catalytic converters or cat converters as it’s often referred to are designed to get rid of unburned fuel from your vehicle’s exhaust system, which results from the normal processes of running the engine.

The fuel that is not used will be released into the air as hydrocarbons that cause air pollution. To help reduce the amount of fuel that is not used, this converter for catalytic conversion is attached to the exhaust system of the vehicle directly behind an exhaust intake manifold. This position is used to warm the catalyst material which causes a thermal reaction that burns the fuel left over.

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How To Replace Catalytic Converter Without Welding:

Magna Flow Catalytic converters that are universal are the fundamental elements of a full range of direct-fit solutions. The major advantage of the catalytic converter universal is the unit can cover a vast range of car makes and models. Catalytic converter prices can vary depending on the manufacturer and the configuration.

The component itself can be priced between $550.00 and $550.00 and $1250.00 as well as the labor is usually somewhere $125.00 between $125.00 and $220.00. There may be a core cost that can be returned when the cat is returned to the retailer or the parts house.

How Long Do Catalytic Converters Last?

A catalytic converter is typically designed to last between 90,000-140,000 miles, but it will lose efficiency faster if the vehicle is driven in a hurry. A cat converter is most effective when the vehicle is driven gently and over long distances.

There could be a myriad of symptoms in the event that your catalytic converter is bad, which range start with a failure to pass the smog test to the engine not having enough power.

Let’s Get Started!

Start with the car supported by the jack stand-up enough to work your exhaust system. Check that the engine is running cold, and the exhaust system is sufficiently cool to work.

Tools and Supplies Needed:

  • Pry bar
  • Set of sockets with universal sockets
  • Wrench set
  • Catalytic converter replacement
  • Shop towels
  • Protective eyewear and gloves

Remove The Catalytic Converter:

Before you remove the catalytic converter it is recommended of spraying WD40 into the mounting nuts and bolts to aid in removing the rust that is typically found on exhaust systems.

Spray on the exhaust pipe flange in front as well as the connection bolts for the tailpipe flange. As the anti-rust liquid is settling, find and unplug those oxygen sensors’ electrical connections. They are located in the converter catalytic, and often inside the pipe that heads.

The connectors will be fitted with safety clips that need to be pulled inwards before they can be removed by gently pulling them out. Follow the wiring, and then remove the oxygen sensor wire from their holders. Then safely move them out of the way to ensure they aren’t damaged when taking off the catalytic converter.

Many catalytic converters feature heat shields to shield heat from the undercarriage of the vehicle. To access certain bolts for mounting, the shields might require removal. After the anti-rust liquid has sat for some time, make use of a 14-mm, 15-mm, or 17-millimeter socket wrench to take off these bolts, turning counterclockwise.

It is possible that you will require an extension tool to aid in the removal. A universal socket can also help. The bolts or nuts you use may be tight and a little rusty, so you should be prepared to exert some force on them.

How To Repair Catalytic Converter:

Remove the coupler for the exhaust pipe mounting bolts by using a 15 mm or 17 mm wrench or socket located at the back of the catalytic converter. Every application is different and some will require cutting with hacksaws and then welding after the catalytic converter has been fitted.

They also offer a repair of exhaust pipes which is basically a clamp, which is available from Amazon or from your local hardware store to join the pipes. After the clamps are loose, use a pry bar to loosen the clamps and assist during the removal. This will allow for an opening between the clamp and the exhaust pipe.

Once the rear exhaust mounting is removed, use the hammer made of rubber or plastic to break the muffler off and the outlet for the catalytic converter. Grab the converter’s catalytic converter using two hands and pull it to the exhaust manifold as well as the back exhaust systems.

Some converters with catalytic features have the option of a heat shield, which could be sharp, so be careful to avoid cutting yourself.

Remove The Oxygen Sensors:

Certain catalytic converters come with multiple oxygen sensors, which have to be identified to prevent confusion when assembling. Tape can be used to label the location of the sensor so that they are able to be installed inside the new catalytic converter.

Don’t mix them up as the wiring connectors are distinct and do not connect to the wire harness that is used for the primary wiring. Apply WD40 to the sensors to assist in the removal.

After successful labeling, take all the sensors out of the catalytic converter that was previously used with a 7/8 or 22 mm wrench, turning them counterclockwise. Then, set them aside.

Clean The Gasket Surface:

  • In the exhaust manifold, there is a gasket that must be free of dirt, corrosion, and the old gasket material that was left over from the catalytic converter that was previously in use.
  • Make use of a gasket scraper or a wire brush for the gasket’s sealing surface.
  • This will assist the new gasket to adhere to the sealing surface and stop leaks.
  • Place the new gasket in its place by hanging it on the manifold studs for the exhaust and the header pipe on the converter.

How To Replace Catalytic Converter Without Welding:

Install the Oxygen Sensors:

  • Install the oxygen sensors with labels onto the catalytic converter and place them in their proper positions.
  • Connect the oxygen sensors manually to prevent cross-threading.
  • It’s recommended to add a tiny amount of anti-seize on the threads for mounting to help in the removal of the oxygen sensor when replacement is needed.

Install The New Catalytic Converter:

  • The catalytic converter has been installed and is now ready to be installed.
  • Carefully place the catalytic converter to the exhaust manifold flange and make sure that the gasket remains in place.
  • The flange coupler is located on the head pipe to the manifold’s exhaust studs.
  • Certain applications may employ nuts in place of bolts.
  • In this case, you simply need to place the bolt holes in the right direction.
  • Make sure you thread the bolts or nuts that mount but don’t tighten them.
  • Make use of a socket for picking off any slack, while making them loose.
  • The final tightening is done after the rear end of the catalytic converter is placed in position and connected.
  • If you tighten the bolts or nuts too quickly, they will create stress and possibly leak since the unit needs to be pushed into place for the connection to the back of the converter.
  • Attach and secure the bolts for mounting couplers located at the back of the catalytic converter.
  • The coupler is able to slide over the pipe and be pulled downwards to the exhaust pipe in the rear.
  • Make sure that the bolts are tight and then tighten on the top of the catalytic converter flange nuts, or bolts.
  • The torque requirements for each are between 25 and 30 feet pounds.

Reconnect The Oxygen Sensors:

  • Lift the oxygen sensors connectors out of their safe location and begin to connect them.
  • Connect the connectors so that you can hear clicks that confirm that they have been reconnected.
  • The wires should be inserted into their holders, which are plastic, and away from the path of the catalytic converter.
  • This will prevent melting the wires that could trigger the Check Engine Light to illuminate.
  • Install any heat shields or exhaust mounts for the system that were removed during the work and you’re good to go.
  • In the event that the engine check was turned off because of the catalytic converter not working properly, the codes need to be removed.


Replacing a catalytic converter without welding is an accessible process that can be completed with the right tools and preparation. By following the steps outlined in this guide, anyone can replace their catalytic converter and restore their vehicle’s engine performance and emissions to optimal levels.

It’s important to remember that catalytic converters are crucial components of a vehicle’s exhaust system, and their proper functioning is essential for the environment and the longevity of the vehicle. Therefore, it’s important to address any issues with the catalytic converter promptly and accurately.

With the knowledge and confidence gained from this guide, replacing a catalytic converter without welding can be a straightforward and successful process.

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