8 Best Catalytic Converter Cleaners (for Clogged Cats)
Catalytic converters (not “Cadillac converters” as some may say) reduce engine exhaust toxicity, but over time can get dirty or damaged. While replacement is needed for failed converters, cleaners can often restore dirty ones to proper function.
But with so many options, how can you know which catalytic converter cleaners actually work? I’ve tried many catalytic converter cleaners over the years and here are the only ones I can recommend.
See Also: How to Clean a Catalytic Converter (2 Methods)
Top 8 Catalytic Converter Cleaners
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. Here are ones we recommend.
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 and is easy to use.
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.
See Also: Tips to Pass a State Emissions Test
#2 – CRC “Guaranteed to Pass” Emissions System Formula
The 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
In 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
Made 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.
Read Also: Is Driving Without a Catalytic Converter Legal?
#5 – Dura Lube Severe Catalytic and Exhaust Treatment
Dura Lube’s Severe Catalytic and Exhaust Treatment is a heavy-duty cleaner for your car’s exhaust system. This 16-ounce bottle is designed to tackle stubborn buildup that can mess with your catalytic converter and exhaust.
While it’s not mentioned as often as some other brands, it’s a good, inexpensive option to try before considering a costly catalytic converter replacement. It works by breaking down carbon deposits and other gunk as you drive, potentially improving your engine’s performance and reducing emissions.
Simply add an entire bottle to about 16 gallons of fuel in your gas tank.
#6 – Sledgehammer Run-Rite Kit
The 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
While 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
Like 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.
How Catalytic Cleaners Work
Ever wonder how these miracle-in-a-bottle cleaners actually do their job? Well, it’s not magic, but it is pretty cool chemistry.
Catalytic converter cleaners are basically souped-up fuel additives that you pour into your gas tank (in most cases). As you drive, this special formula mixes with your fuel and gets burned in the engine.
The cleaner then travels through your exhaust system, including the catalytic converter. It’s designed to break down carbon deposits, soot, and other nasty gunk that’s built up over time. Think of it like a deep cleaning for your car’s insides.
These cleaners often contain solvents and detergents that dissolve the buildup, allowing it to be burned off or expelled through the exhaust. Some even have compounds that can help “reactivate” the precious metals in your converter, improving its efficiency.
The key is that they work while your engine is running and hot. That heat, combined with the cleaner, helps to burn off the deposits more effectively. It’s not an instant fix and you’ll usually need to drive for a while to see results. In some cases, more than one treatment is necessary. But for many cars, it can make a noticeable difference in performance and emissions.
When Cleaning Isn’t Enough
Sometimes even the best cleaner can’t save a catalytic converter that’s too far gone. It might simply be too clogged or actual internal damage may have occurred.
If you’ve tried a couple of different cleaners and your car’s still running rough, failing emissions tests, or that pesky check engine light won’t go away, it might be time to bite the bullet and replace your catalytic converter.
Watch out for signs like a sulfur smell (think rotten eggs), excessive exhaust smoke, or a noticeable drop in engine performance that doesn’t improve with cleaning. These could mean your converter is physically damaged, melted, or just plain worn out.
Another red flag is if your car’s making a rattling noise, especially when you start it up. That could mean the honeycomb structure inside the converter has broken apart. No amount of cleaner is going to fix that.
Remember, catalytic converters aren’t designed to last forever. If your car’s getting up there in miles (usually 150,000+), replacement might just be part of the game. It’s not cheap, but it’s cheaper than damaging your engine by trying to limp along with a busted converter.
And if you’re thinking of simply removing the cat altogether, there’s quite a few reasons why you wouldn’t want to do that.
He’s known for his attention to detail and problem-solving skills and enjoys coming up with out-of-the box solutions when the situation requires it.
When he's not troubleshooting customers' cars, you'll most likely find him working on his current project ('96 Bronco) or cooking Italian food for his family.
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I have a 2004 Nissan altima sl 2.5. I’m not sure what part of the catalytic converter l need to replace? The manifold or the catalytic converter that’s attached to the exhaust system. Can you tell me what part l need to replace. I know it’s the Cat due to it falls under 4 of the 6 symptoms described.
I’m not sure where the catalytic converter sits on that vehicle. I’d look at a diagram from the manufacturer if you can. Check to see if Nissan’s site has such a diagram with the different parts of the exhaust and their respective part numbers.
I have 2011 Chevy equinox that I put in a can of sea foam due to hearing a rattling noise but it did not clear it but made it louder can I put in a catalytic cleaner in on top of the sea foam. It’s not showing codes but when I start the engine it’s very loud.
Sure you could swap the catalytic converter, but I’m not sure it would fix the issue. You may want to see if the owner’s manual calls for a valve adjustment in that car. Before you do that, try to figure out if the noise is coming from the top end or the bottom end of the engine.
Did you ever figure this out? What happened?
1993 jeep GC with 6 cyc. Won’t pass california smog due to high HC at idle. 36 pts above the limit. It does pass high speed HC limits no problem. Has new ignition parts and ran SeaFoam through it via the throttle body. Has 200k miles but runs good. Could it be a bad or dirty Cat? It is the original unit. Do you think using this cleaner will be worth it? How do you tell if it is working? Measure the input and output temp.?
I don’t know, I don’t live in California so I have never dealt with their smog test. Have you tried cleaning the throttle body, MAF if it has one, and IAC valve? If it otherwise passes smog, my thoughts are that some of the idle control components may be dirty.
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.
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
Hi!
Could I add Seafoam kind plus another actual catalytic converter cleaner to my fuel tank? Or would that be too much going on?
I don’t advise mixing chemicals unless the label specifically says to do so, to avoid the risk of dangerous reactions.
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
I suppose it’s possible, but I think it’s unlikely. If you want some factors that will improve your fuel economy, check out this article: http://cartreatments.com/bad-gas-mileage/.
If I have already added Lucas fuel treatment can I use cats clean in the same tank of gas?
Don’t recommend. Stick with Lucas and repeat per instructions and you should be fine.
Not advisable. There is a ratio of gas vs cleaner for the amount of gas in your tank.
Should wait until you’re down to 1/4 tank or approximately 4 gallons of gas in your tank.
Most caty cleaners say to pour into tank containing 1/4 tank of gas, then drive approximately 15 miles & then completely fill your tank with gas. Nothing else should be added in that tank of gas.
Just read the labels on product’s container for exact directions for the caty cleaner you choose to use as it may vary from one brand or product to another.
Motor power care cadalytic
Converter cleaner..where can I buy this product in Canada ?
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.
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.
Just used this product today. Worked as promised, superior results!