8 Best Catalytic Converter Cleaners (for Clogged Cats)

Note: This post may contain affiliate links. This means we may earn a small commission for qualifying purchases at no cost to you.

Last Updated on December 21, 2020

During the internal combustion process of an engine, there are exhaust gases which are emitted as a result of the air and fuel mixture being ignited. These are very toxic gases which could become dangerous pollutants if they were to be released into the air outside.

Fortunately, cars are made with a catalytic converter which reduces the toxicity levels of these gases before they’re released out of the tailpipe. There is a special chemical reaction which allows this to happen when the metals of the converter come in contact with the gases.

The downside to catalytic converters (not “Cadillac converters” as some like to say) is they get dirty. This can occur either from years of using the converter or from a problem with the internal combustion process where there is too much fuel being mixed and the extra fuel that doesn’t get burned ends up damaging the converter.

If the catalytic converter is damaged, even the best catalytic converter cleaner won’t help and replacement will be necessary.

But for instances where it’s just dirty, cleaning the converter can make a huge difference. But do catalytic converter cleaners work? The answer is Yes in many instances as long as you’re dealing with just a dirty catalytic converter.

See Also: How to Clean a Catalytic Converter (2 Methods)

Top 8 Catalytic Converter Cleaners

clean exhaust system

If you ever notice your fuel economy decrease noticeably or a rotten egg smell is coming from your engine, then you need to clean the catalytic converter right away. There are many reputable catalytic converter cleaners available on the market. Below are the top 10 cleaners that are most often recommended.

See Also: 5 Best Throttle Body Cleaners

#1 – Cataclean Engine and Catalytic Converter Cleaner

The 16 oz. bottle of Cataclean is one of the best products you can use to clean your catalytic converter and oxygen sensors. Although it is not cheap, the cleaner has a good reputation of clearing various catalytic converter codes from your ECU.

If you need to take an emissions test and you need to quickly clean your catalytic converter and fuel system, this is probably your best bet.

#2 – CRC “Guaranteed to Pass” Emissions System Formula

best cat cleanerThe CRC “Guaranteed to Pass” formula actually offers a double money-back guarantee so the company stands behind their product. This solution will remove carbon from your engine, catalytic converter, and fuel injectors.

It’s been used many times to successfully treat a P0420 fault code. Good to use to increase your chances of passing an upcoming smog test. Recommended to use every 3,000 miles.

#3 – Solder-It CAT-1

catalytic cleaner reviewsIn addition to being a cleaner, Solder-It is designed to remove the nasty rotten egg smell from toxic gasses because of its deodorizing properties.

For best results, add it to your gas tank when you have about a quarter of a tank full and drive for about 50 miles before refilling. This stuff is best for removing the rotten egg odor but also cleans your cat converter.

#4 – Oxicat Oxygen Sensor and Catalytic Converter Cleaner

clean catalytic converterMade in Germany, Oxicat is designed to clean the entire exhaust system by removing carbon deposits and soot throughout. When used properly (follow the directions!), it does a great job of cleaning, restoring performance, and even clearing out check engine codes such as “catalyst system efficiency below threshold”

As with any other cleaner, it needs the catalytic converter to sustain working temperature while driving so if you cat is damaged or cracked, a cleaner won’t help you.

#5 – Hi-Gear HG3270s

emissions pass cleanerUse Hi-Gear to clean your catalytic converter, exhaust system, fuel system, valves, and pistons. You will likely notice better fuel economy and engine performance after using.

If you’re in danger of failing your emissions test, it’s worth trying and many users have reported it being able to clear out their emissions related trouble code without having to spend hundreds on a new parts.

#6 – Sledgehammer Run-Rite Kit

fuel system cleaner kitThe Sledgehammer Run-Rite kit includes both a bottle of Fuel System Ultra Cleaner and the Rapid Induction Deposit (RID) cleaner to work together in cleaning your fuel and exhaust systems.

This is formulated to get rid of soot and carbon which may exist in the fuel system, particularly the catalytic converter. Since you need to add the contents of RID directly into a vacuum line to release into the intake, it’s not recommended for beginners.

#7 – Sea Foam Motor Treatment

Seafoam engine cleaner reviewWhile the popular Sea Foam treatment won’t clean your catalytic converter, it treats the problems prior to that which cause the converter to get clogged up in the first place.

Many individuals have actually had fault codes related to the catalytic converter go away after using. At the very least, you’ll give your fuel injectors and combustion chamber a good cleaning.

Also Recommended:  Best Fuel Injector Cleaners

#8 – Lucas Fuel Treatment

Lucas fuel treatmentLike Sea Foam, Lucas Fuel Treatment treats the problems of a dirty fuel system which is often responsible for a dirty catalytic converter. By treating those problems, the engine will run cleaner and allow the converter to burn itself clean.

More than one treatment will be necessary but you’ll be treating the root of the issue so it doesn’t occur again.


10 thoughts on “8 Best Catalytic Converter Cleaners (for Clogged Cats)”

  1. We have a repair shop and our customers always ask us about catalyst cleaners. So far the best working cleaner is called Motorpower Care catalytic converter cleaner, we noticed it’s new in market but we are expecting it to be popular in short time for its effectiveness.

  2. I have a Ford Focus, that failed it emissions test this year, the mechanic said to try some cataclean through the engine to resolve it. It was less than £20 and a one week later the car passed the test no problem at all.

  3. Have a 1999 Jeep Grand Cherokee gets very bad gas mileage but runs good and still has power could cat cleaner improve the gas mileage

  4. For my 2007 mazda 3, Can I soak my catalytic converter in a warm water with sea foam auto soap(used for car washing, not the Spray can sea foam) to clean the catalytic converter? Emissions code: PO421

  5. I have a friend that told me he took the cat off his Honda civic and washed it with dish soap and boil.
    Pass the California emissions test.


Leave a Comment