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How to Clean a Catalytic Converter

Nidhi Nangia
By Nidhi Nangia. Updated: March 7, 2018
How to Clean a Catalytic Converter

The catalytic converter is one of the most crucial components of your car’s emission control system. It works by converting harmful emissions from your car’s engine into safe gases and water. Running a car with a faulty or poorly maintained catalytic converter can result in excessive consumption of fuel, loss of the engine power and deteriorated overall performance. Although a catalytic converter will last your car’s lifetime, it needs to be cleaned from time to time to keep working in its optimum condition. Read this oneHOWTO article to know how to clean a catalytic converter.

You may also be interested in: How to Identify Clogged Catalyst Symptoms

Steps to follow:


Park in the right spot. First of all, before your begin cleaning the catalytic converter, park your car on a well-lit, flat and hard surface. Open its hood and make it stable with the help of the prop rod. Doing this will keep your hood open while keeping your hands free. It is best to wear protective eye gear to be on the safe side.

How to Clean a Catalytic Converter - Step 1

Remove bolts. The next step is to grab a wrench and loosen the bolts that secure your catalytic converter in its position. Remove the bolts and keep them in a safe place so that you can quickly find them when needed again. Once you have removed all the bolts, carefully remove the converter from the exhaust system.


Wipe off residue. Use a piece of cloth to wipe off any residue from the external face of the catalytic converter. Use a power washer to apply force on the converter so that any built-up debris can be easily blown out. Give special attention to the outlet and inlet pipes of the converter. If they are still dirty, you will need to soak the converter in a mixture of hot water and degreaser, and then rinse off with distilled water. There are plenty of degreasing agents available in the market, but if don’t want to buy one, you can use a mixture of soap and hot water as well. Make sure that the soap you use should be residue free and powerful. Before you reinstall the converter, make sure that all the soapy water has been removed from the surface, as it may leave residue on the active surfaces of the converter after drying.


Dry it out. Once you have cleaned and rinsed the converter, allow it to dry completely and position it back on the exhaust system.


Secure the bolts. After placing the converter in its position, secure it in place using the bolts you unbolted earlier. Now close the hood of the car, drive your car for a few minutes and see if it is still losing power.


Give it a test drive. Once you have cleaned your catalytic converter, take your car to a highway and drive at for around 1-2 miles. Quickly slow down the car and accelerate again to see if the acceleration has improved or not. If you feel the difference, then it indicates that you have successfully cleaned your converter and any clogs have gone. Also keep an eye on your car’s mileage. If you have successfully cleaned your catalytic converter, you will definitely notice an improvement in your gas mileage, and you will need fewer fuel.

How to Clean a Catalytic Converter - Step 6

Not working? If you do not see any difference, then you will need to take your car for a carbon cleaning or hydrogen treatment process. Another option some people choose is to install a straight pipe in place of a catalytic converter, but that would cause significant environmental damage. Not only that, but it would not pass an emissions test or an MOT as it is illegal. The last viable option is to get your catalytic converter replaced with a new one.

If you want to read similar articles to How to Clean a Catalytic Converter, we recommend you visit our Car Maintenance and Repair category.

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1 comment
Soooo just replace the catalytic converter with a straight thru tail pipe ... oh YEAH? what country do YOU live in... There is NO state in the USA where that is legal & you would NOT pass emissions (DEQ) ......THUMBS DOWN for BAAAAD ADVICE
OneHowTo Editor
Hey Rick,

The original article did speak about the environmental harm this would do. All it was saying was that technically you could replace it with a straight pipe, but we did not recommend it as an option. Perhaps the text was unclear to you, so we have updated it to ensure there will be no confusion.
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How to Clean a Catalytic Converter