How To Clean A Catalytic Converter

Here's a super simple guide on how to clean a catalytic converter without removing it. Unclog your catalytic converter without much effort!

The catalytic converter cleans the toxic gases made by the engine’s combustion. However, sometimes the catalytic converter itself is needed to be cleaned.

There are two ways to clean a catalytic converter. The first way is to clean the catalytic converter without removing it by adding a cleaning product to the fuel tank.

The more effective and time-consuming way is to remove the catalytic converter and soak it overnight.

The most significant advantage of cleaning or unclogging the catalytic converter is that it may make it work satisfactorily again, and you do not have to buy a brand-new one.

We will explore both ways to clean the catalytic converter so that you may save several hundred, if not thousands, of dollars.

Let’s get into it!

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Should You Clean Your Catalytic Converter?

catalytic converter repair

Before you start cleaning the catalytic converter, you should be aware that there are scenarios where cleaning the catalytic converter will be ineffective.

Also, you should keep in mind that if your catalytic converter has become faulty, there is probably another underlying problem that made it dirty in the first place.

If you clean the catalytic converter without resolving the initial issue, your catalytic converter will clog again after you have cleaned it.

If your catalytic converter has turned bad due to structural damage, cleaning it won’t help. Instead, you would have to buy a new one and replace the old catalytic converter.

Unfortunately, replacing the catalytic converter can be relatively expensive, and the whole process is tightly regulated and should be documented according to the law.

How To Clean A Catalytic Converter Without Removing It

Can You Drive Without A Catalytic Converter

The easiest way to clean a catalytic converter is to use a catalytic converter cleaner that goes into your fuel tank.

There are several catalytic converters cleaners in the market to buy, and it is tough to differentiate which are good and which are not.

Some people would advise using lacquer thinner as a cleaner. It has worked for many people, but there has been some concern that it may damage the fuel lines.

When cleaning the catalytic converter, follow the instructions for the cleaner of your choice.

If you decide to use lacquer thinner, put 3 gallons of lacquer thinner into your half-filled fuel tank.

When the cleaner of your choice is in the fuel tank, take the car for a spin on the highway and drive 100-150 miles.

If you prefer to stay in the spot, you can put the car in neutral and rev the car at around 3000 RPMs for half an hour.

If that does not do the trick, you could try to remove the catalytic converter and clean it more thoroughly.

Remove And Clean The Catalytic Converter

catalytic converter replacement and repair cost

Removing the catalytic converter to clean it is a greater hassle; however, the results are usually better than simply using a catalytic converter cleaner and putting it in the fuel tank.

To remove the catalytic converter, you need to safely get access under the car and then unscrew the bolts.

Keep in mind that the catalytic converter gets extremely hot when operating. Because of that, make sure it cools down before you start working with it.

Also, not getting the bolts off on the first try should not discourage you, as the extreme temperature of the catalytic converter has made the bolts stick very tight.

When the catalytic converter has been removed, take a bucket or container, and fill it with water and laundry detergent soap.

Let the catalytic converter stay overnight, and you should have a clean catalytic converter when you wake up the next day. If so, simply put the catalytic converter back and enjoy!

What To Do If Cleaning Does Not Work?

Catalytic Converter Cleaner Catalyst

If you have tried cleaning the catalytic converter by removing it and following the abovementioned steps but still get a check engine light or an error code, you should consider a few steps.

It may happen that your catalytic converter was not clogged at all, but another issue was causing the check engine light/code.

For example, it may be that your O2 sensor has gone bad or that your car is running too rich/lean for other reasons.

Check out our article regarding symptoms of a bad catalytic converter to get a better picture of where the problem may actually be.

Also, as mentioned many times, you must make sure to resolve the main issue that caused the catalytic converter to clog in the first place.


Symptoms Of A Bad Catalytic Converter

The catalytic converter may produce a code and cause various symptoms if it becomes clogged.

You can save hundreds of dollars by cleaning the catalytic converter instead of replacing it, provided that the issues resolve after you have cleaned it.

When it comes to cleaning the catalytic converter, there are two main approaches.

Either you can add a catalytic converter cleaner to your fuel tank or remove the catalytic converter and soak it overnight.

Keep in mind that catalytic converters can be extremely hot. Make sure it has cooled down before you do any work that requires you to handle the catalytic converter.

The latter of these two options usually has a greater success rate, but it is also much more time-consuming and physically tiresome.

In some cases, neither of these two methods will be effective, and the only option left available is to replace the catalytic converter, which is not very cheap.

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Bajro Muric

Bajro is an ASE-certified master technician and car enthusiast with a love for writing and teaching. He writes about anything regarding cars, from common problems and fixes to racing.