How to Clean the Catalytic Converter

Over time, the catalytic converter can experience build up from carbon making it difficult for it to function properly and eliminate the unsafe emissions from your exhaust and your check engine light may come on. Just like you would do with a performance exhaust, you need to see what’s wrong with it and fix the issues. In most cases, it is a better option to just replace the converter. However, there are products on the market that claim to help you figure out how to clean a catalytic converter. If you are low on cash and just need a bit more time before a replacement can be obtained, this may be an option for you. This article will give you step by step instructions on how to clean catalytic converter.

Things You Will Need

  • Wrench;
  • Small Container;
  • Shop Cloth;
  • Power washer;
  • Degreaser (or soap and hot water);
  • Old Towel;
  • Protective eyewear and gloves.

Step 1: Safety First

The first step in how to clean catalytic converter is to take precaution to ensure your safety through the process. First, you need to make sure you understand how this works. During regular driving, a vehicle produces harmful pollutants. It is the catalytic converter’s job to take those pollutants and transform them into a gas that is not as toxic to the environment. In order to accomplish this, the catalytic converter is made up of certain metals that create a chemical reaction with the fumes from the engine.

Use protective wear including eyewear and gloves. Also, be sure your vehicle is placed on a hard, flat surface that has plenty of light. Using the hood rod, prop open your vehicle’s hood and check to make sure it is securely up to avoid any possibility of it falling closed while you work underneath it.

Step 2: Converter Removal

Use the wrench to loosen and remove the bolts securing the catalytic converter to the exhaust system. Place the removed bolts into the small container for safekeeping to make replacing them easier later. The next thing you need to do to go through the process of how to clean catalytic converter is to remove the actual converter from its position.

Step 3: Cleaning

The next step in the process of how to clean catalytic converter is to begin cleaning. First, use a shop cloth and degreasing agent to clean any residue from the outer housing. Next, use a strong setting on your power washer and use it to apply some force to the converter to help break up the built-up debris. Be sure to focus on the inlet and outlet pipes. Once you finish this step, use the degreasing agent or commercial catalytic converter cleaner of your choice with some hot water and soak the converter in it to get any remaining dirt and deposits free. After a good soak, rinse the converter clean with some distilled water. If you choose to forgo the commercial cleaners, a strong, residue-free, clean rinsing detergent mixed at a 1:1 ratio with hot water has been found to be successful in cleaning leftover debris and gunk from the converter.

Step 4: Drying

Once your cleaning process is complete, give the converter a good once-over to be sure you have successfully cleaned the inside. Also, ensure there is no leftover soap on the surfaces. This is because you do not want any soap residue left behind to dry onto the active surfaces of the converter. Before you are able to replace the catalytic converter back into position, you must dry it completely. Take the old towel and lay it on a flat surface. Allow the catalytic converter to lie on the towel to dry. You may periodically want to rotate the converter to get the droplets inside to dry faster. Allow 12 to 24 hours for complete drying to take place.

Step 5: Replace

Once the converter is fully dry, place it back into position under the hood. Grab your container of bolts and re-secure the converter back into place. At this point, if you choose to not use a commercial cleaner, you can close up shop and give your vehicle a test drive. Warm your vehicle up by driving for a few miles on the highway. Then, on a regular road, quickly slow and accelerate to see if your response time has improved. If you can feel a difference, you just bought yourself some time with your old converter and should see appositive change in your fuel economy.

If you fail to see any positive results, you can move on to the optional step in this process of how to clean catalytic converter. Otherwise, it may just be time for a replacement.

Step 6: Commercial Cleaner (Optional)

To further clean your converter, commercial cleaners such as Cataclean are available. This is the basic cleaning process for most of these cleaners:

  • Pour the bottle of cleaner into your gas tank.
  • Drive your vehicle until you use most of your gas. This will ensure that you use most of the cleaning chemicals.
  • Clear any error codes detected by your OBDII scanner.
  • Fill your gas tank up to full.
  • Re-calibrate your system by driving for about 50 miles both on city streets and highways.


Learning how to clean catalytic converter parts on your own is not a difficult thing to do. Though most of the time it is wiser to just get a replacement, many have found success in cleaning their converters to get some more use out of their old one. You can follow these basic steps with or without the use of a commercial solution to see if you can hold off on replacing your catalytic converter altogether. This could be a great, cheap option if you need to buy sometime before you are able to replace the part, get to a shop, or have time to do the replacement.

Have you found success with cleaning instead of replacing your converter? Do you have any products to suggest or tell others to steer clear of because of your experience with them? Please leave any helpful tips for others attempting to clean their catalytic converters below.

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