How to Install a Catalytic Converter Without Welding?

Installing a catalytic converter without welding can be handy for any DIY car enthusiast. While the welded version offers a permanent solution, clamping your new catalytic converter into place offers a relatively straightforward and reversible alternative. Here’s a guide on how to install a catalytic converter without welding, saving you a trip to the mechanic and possibly a good amount of money.

how to install a catalytic converter

Tools You’ll Need

  1. Jack and Jack Stands
  2. Socket Wrench Set
  3. Adjustable Wrench
  4. Metal Saw (optional)
  5. Measuring Tape
  6. Clamps suitable for exhaust systems
  7. High-temperature exhaust sealant
  8. Gloves
  9. Safety Glasses
  10. Respirator Mask

How to Install a Catalytic Converter without Welding?

Before you begin, ensure that your car is in a well-ventilated area and the engine has cooled down. Wear appropriate safety gear and follow the below step-by-step guide.

Step 1: Lifting Your Car

First, use a jack to lift the front end of your car. Secure it with jack stands once it’s high enough for you to work under. This will allow you easier access to the underbelly of your vehicle, where the catalytic converter is located.

Step 2: Identify and Remove Old Catalytic Converter

Locate your old catalytic converter. It should be part of the exhaust system, typically between the exhaust manifold and the muffler. Remove the bolts that secure the bad catalytic converter to the exhaust system using your socket wrench set. You may also encounter rusty or seized bolts; applying a penetrating oil can help in such cases.

Step 3: Measure and Cut (If Necessary)

Measure the new catalytic converter and compare its dimensions with the old one. You may need to cut the existing exhaust pipe to ensure a good fit if they are not identical. Use a metal saw for this, and always measure twice before cutting.

Step 4: Clean the Flanges

Before installing the new catalytic converter, clean the flanges on the exhaust pipe where the old converter was mounted. This ensures a better fit and reduces the chance of leaks.

Step 5: Apply Exhaust Sealant

Apply a high-temperature exhaust sealant to the areas where the new catalytic converter will attach to the existing exhaust system. This helps create a gas-tight seal.

Step 6: Position the New Catalytic Converter

Carefully slide the new catalytic converter into place, ensuring it’s correctly oriented (most have an ‘inlet’ and ‘outlet’ side). The exhaust sealant should help it stick in place temporarily.

Step 7: Clamping

Place your clamps around the edges of the catalytic converter and the existing exhaust pipes. Tighten them using your adjustable wrench, but don’t overtighten, as you could deform the pipes.

Step 8: Inspect for Leaks

Before lowering your vehicle, start the engine and inspect for leaks around the exhaust manifold. If you see or hear leaks, you may need to tighten the clamps further or apply more exhaust sealant.

Step 9: Lower the Vehicle

Once you’re satisfied with your installation, carefully remove the jack stands and lower your vehicle using the jack.

Step 10: Road Test

Perform a road test to make sure everything is functioning as it should. Listen for unusual noises and monitor for any signs of decreased performance or warning lights on your dashboard.

Installing Catalytic Converter YouTube

Can You Install a Catalytic Converter Yourself?

Yes, installing a catalytic converter can be a doable task for those who have some mechanical skills and the proper tools. However, the complexity of the installation can vary depending on the design of your vehicle’s exhaust system, the type of catalytic converter you’re installing, and whether you choose to weld or clamp it into place.


Before taking on this task, it’s advisable to have:

  1. Basic Mechanical Skills: Understanding the basics of car repair and maintenance is essential.
  2. Tools: You’ll need various tools, including a jack, jack stands, wrenches, and possibly a metal saw, among others.
  3. Safety Gear: Safety equipment like gloves, safety glasses, and a well-ventilated work area are essential for your safety.
  4. New Catalytic Converter: Ensure you have the correct catalytic converter for your vehicle’s make, model, and year.

Does a Catalytic Converter Need to Be Welded On?

Installing a catalytic converter does not necessarily require welding, although welding is often considered the most permanent and secure attachment method. There are alternatives, such as using exhaust clamps and high-temperature sealant, to attach a new catalytic converter to the existing exhaust system.

Is it Better to Weld or Clamp Exhaust?

Here, we have shared the advantages and disadvantages of both welding and clamping of catalytic converters.



  1. Permanent Solution: Once it’s welded into place, the catalytic converter is securely attached and unlikely to come loose.
  2. Leak-Proof: Welding can ensure a gas-tight seal, meaning exhaust gases are less likely to escape, ensuring better emissions control.
  3. Better Flow: A welded connection generally allows for a smoother flow of exhaust gases through the system, which can improve vehicle performance.


  1. Requires Expertise: Welding requires specialized equipment and expertise. For those not experienced with welding, this could mean a trip to the auto mechanic.
  2. Less Flexibility: Once welded, removing the catalytic converter is not easy if you need to replace it or make other modifications.
  3. Cost: Welding usually adds to the labor cost of the installation.



  1. Ease of Installation: Clamping is generally easier and quicker than welding, making it a more accessible option for DIY enthusiasts.
  2. Flexibility: If you need to replace the catalytic converter in the future, a clamped installation is generally easier to remove.
  3. Lower Cost: Avoiding the welding process can save on installation costs.


  1. Potential for Leaks: Clamped connections are more likely to develop leaks than welded connections.
  2. Security: A clamped catalytic converter is easier to steal than a welded one.
  3. Flow Disruption: The clamps and joints may cause some disruption to the smooth flow of exhaust gases, potentially affecting vehicle performance.

Both methods have pros and cons, and the best method for you may depend on your specific needs for replacement, the vehicle you’re working on, and your level of mechanical skill. If in doubt, consult a professional for advice tailored to your situation.

Final Thoughts

Following the abovementioned steps and taking proper precautions, installing a catalytic converter without welding can be a straightforward task. If you encounter any difficulties or are unsure, consider seeking professional assistance to ensure a safe and effective installation. A poorly installed catalytic converter can impair vehicle performance and be a safety hazard. Always follow the manufacturer’s guidelines and specifications when doing any form of automotive DIY.


Mr. Shafiqule Islam is a graduated Mechanical Engineer and has more than 15 years experience of repairing and maintenance of different brand vehicles like Toyota, Mitsubishi, Ford, Mercedes, BMW etc. He is also giving training to Mechanics. He has started writing to share his practical knowledge to Vehicle Owners, Drivers and Mechanics to keep their cars at best fit.

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