How to Clean a Catalytic Converter (2 Methods with Guide)

Jerry Wilson
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Method 1: Cleaning without Removing Catalytic Converter

Some people would go for this method because it’s cheaper. But this method should only be taken if you are not experienced enough to handle the wire brush method.

Go over the catalytic converter with a garden hose turned on – full blast, with a garden nozzle, and try to blast it as hard as you can. A pressure washer can also be used for better results.

Use a long-handled brush to scrub at the converter. Make sure that you don’t use the brush to reach the inside of the converter.

After you have scrubbed the converter, drive your car for about 20 minutes, or until you can smell the exhaust fumes coming from the converter. If you are driving to your destination, do not accelerate or drive at high speeds. Driving slowly will allow you to smell the fumes, which are really gases that are coming from the converter. Once you smell them, park your car and go through the steps starting from 1.

If you are not interested in doing that, you can also detach the converter and get rid of the particulate with a power washer.

__Tip: You should also check the heat range of your car’s exhaust system, since the catalytic converter works best at its most efficient temperature.

Method 2: Cleaning by Removing Catalytic Converter

This Method Is Only Suitable For Those Working On A Supported Hood With Easy Access To Undercarriage. Do Not Attempt This Method If There Is Not Enough Space To Lay The Catalytic Converter Flat On A Table. Some Models Also Require The Use Of A Protective Rubber Boot.

Follow Directions For Method 1 First, And Then Continue.

Method 2a: The easiest way to remove converter is to disconnect all of its emission hoses.

Method 2b: Here are tools you can use in the work.

Safety Tip: Wear protective gloves, eyes, and clothing.

{1}. Put a piece of wood to protect the vehicle undercarriage
{2}. Remove the bolts and nuts that connect converter to the exhaust pipe.
{3}. Disconnect all emission hoses.
{4}. Put the converter with hoses to a separate place.

Method 2c: Start to clean the converter if you are sure it cannot be used anymore. The converter contains precious metals, so be careful what you throw out.

{1}. Strips covering all hoses as well as hose clamps.
{2}. Use a screwdriver to remove screws securing heat exchanger housing.


If you want to clean a catalytic converter, the process is relatively simple. You have two easy options: take it to a professional or clean it yourself.

Used Motor Oil (1) and Methyl Alcohol (2)

To clean a catalytic converter in your own garage, you’ll need gasoline (3), a funnel (4), a micronutrient cleaner made for catalytic converters (5), a catalytic converter wrench (6), and a rag (7).

Start by removing the dirty filter (8). Pour the cleaner through the funnel into the converter (9). Replace the dirty filter (10) and secure it with the wrench.

Then add about 10 gallons of gas through the funnel into the converter until you notice that the liquid trickled out.

Go to the catalytic converter assembly. Squeeze the throttle body until gas comes out, and then turn off the vehicle (11). Open the fuel filler panel (12) and keep a rag there to protect the interior if the gas trickles.

Connect your favorite air compressor to the battery (13) and let it run overnight.

Finally, check the fuel filter in the gas tank and ensure that it’s clear of gasoline.