Best Catalytic Converter Cleaner

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Having served for some period, carbon buildup blocks the catalytic converter, leading to non-efficient filtering of exhaust gases. You can find out about this malfunction by getting the “Service Engine” light from the car.

Basically, there is nothing difficult in cleaning the catalytic converter with the special cleaner. In this article, we’d like to share some tips on cleaning the converters and representing the best catalytic converter cleaners.

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Best Catalytic Converter Cleaner Reviews

The fuel system in an internal combustion engine mixes air with the gas (air and fuel mixture) to make the exhaust. The gas is toxic and could be harmful if it goes into the sky. To prevent that, a thing called a catalytic converter was created to catch the gas before it can go into the sky.

They decrease the level of gas toxicity before they leave the tailpipe. It happens because of the specific chemical reaction, ensuring the process when the converter metals contact gases.

Catalytic converters are a crucial component in the emission control system of an automobile. Without it, you can’t pass an emissions test. The best catalytic converter cleaners will remove any impurities from the car’s exhaust and ensure that it runs at peak performance. There are many different products on the market, but we have found the seven best catalytic converter cleaners to share reviews with you below!


Overall Best Catalytic Converter Cleaner – DURA LUBE Severe Catalytic and Exhaust Cleaner

DURA LUBE Severe Catalytic and Exhaust Treatment Emissions Test Catalytic Cleaner 16 fl. oz, 1 Pack, HL-402409
1,319 Reviews
DURA LUBE Severe Catalytic and Exhaust Treatment Emissions Test Catalytic Cleaner 16 fl. oz, 1 Pack, HL-402409
  • Use when warning light is activated
  • Use before or prior to replacing catalytic converter
  • Protects catalytic system from oil poisons
  • Reduces phosphorus and zinc retention levels at catalyst inlet
  • Lowers tail pipe emissions

The exhaust system cleaner is highly concentrated and is ideal for cleaning the catalyst converter. It is long-lasting and 100% safe for all vehicles.

You need to pour one bottle into 60 liters (16 gallons) of fuel or 30 mL per 3.8 liters (1-Ounce per Gallon). Last up to 3 months or 5,000 miles – whichever comes first.


Mr. Gasket Cataclean

Cataclean 120007 Complete Engine, Fuel and Exhaust System Cleaner, 473 Milliliter
3,757 Reviews
Cataclean 120007 Complete Engine, Fuel and Exhaust System Cleaner, 473 Milliliter
  • Using Cataclean can lower your total hydrocarbon emissions by up to 50 percent
  • Reduces carbon build-up in catalytic converter, oxygen sensors, fuel injectors and cylinder heads which results in improved fuel efficiency
  • Improves overall vehicle performance-including driveability issues such as power reduction, hesitation, rough idle, hard starts and lost fuel economy
  • Safe for gasoline, diesel, hybrid and flex-fuel vehicles; does not alter fuel
  • Not for use in 2-stroke or oil / gas mix engines

Cataclean is often associated with premium products of high quality. To show that their product can decrease hydrocarbon emissions by up to 50%, the brand tested it at independent laboratories. Thus, by applying this cleaner, you have really high chance to pass the emissions test successfully.

This catalytic converter cleaner is compatible with many kinds of motors. So, the owners of diesel and hybrid cars can surely acquire it. Moreover, choosing products for such motors is rather scarce, especially if you seek really efficient ones.

In addition to cleaning, the Cataclean item deals with preventing thick carbon layering in the future. And that’s its main benefit, which seems to be a great long-term investment. The item doesn’t only solve the problem but protects from it as well. Of course, carbon deposits will appear, but the brand assures that their amount will be reduced. However, note that it’s not suitable for 2-stroke motors.

This catalytic converter cleaner comes in a 16-oz bottle. You are free to save money by buying a pack of 2 or 5 bottles.

  • Made in the USA;
  • 50 state legal and complies with VOC (including California) and OTC regulations;
  • 1 bottle per fuel tank 4 times a year (every 3 months or 5,000 miles).


CRC 05063 Guaranteed To Pass Emissions Test Formula Catalytic Converter Cleaner

CRC Guaranteed to Pass Emissions Test Formula, 12 Fluid Ounce
1,951 Reviews
CRC Guaranteed to Pass Emissions Test Formula, 12 Fluid Ounce
  • Reduces emissions and improves performance in one tank full
  • Powerful detergent additives super-clean the entire fuel system
  • Use every 3,000 miles to improve fuel economy, acceleration and reduce emissions
  • Maximum allowable cleaning chemistry for superior results.
  • Works with all gasoline and ethanol blended fuels.

In its advertising campaign, CRC states that its catalytic converter cleaner will surely help you pass the emissions test. If not, they promise to give your money back and double the sum spent on their product. And such a claim by a respectable company makes this item extremely attractive for many car owners.

This catalytic converter cleaner goes in a 12-oz plastic bottle, which is recommended for 16 gallons of fuel. It works great with all types of ethanol and gasoline blended fuels. Featuring a very concentrated formula, this item performs its duties fast and efficiently. This formula will remove any inordinate amount of carbon within your engine, catalytic converter and fuel injectors.

The brand advises using their cleaner after every 3,000 miles run if you aspire to maintain a low emissions and fuel economy level. The price is relatively affordable. Moreover, you can acquire the 12-pack version of the product and save some money.

The item will not harm the oxygen sensor. But, despite that, it is applicable for gas engines only, and the brand says nothing about its adherence to emission laws.

  • One bottle per full fuel tank (or 2 bottle tanks over 16 gallons).
  • Drive the vehicle normally until the tank is nearly empty (1/8 tank) to ensure the gas mixed with the product has been used.
  • Refill your tank to FULL right before testing.


BoostUp Catalytic Converter Cleaner

SAFE for gasoline, diesel, hybrid, and flex-fuel vehicles; does not alter fuel. Not for use in 2-stroke or oil/gas mix engines.

Proper fuel and exhaust flow will keep that engine running cleaner, smoother, and better, which will also cut down on maintenance costs.


Oxicat Oxygen Sensor & Catalytic Converter Cleaner

OXICAT Oxygen Sensor & Catalytic Converter Cleaner
1,094 Reviews
OXICAT Oxygen Sensor & Catalytic Converter Cleaner
  • Safe and effective for all petrol (gasoline)and diesel vehicles
  • Engineered to clean the entire exhaust system WITH REGULAR USE.
  • OXICAT is activated when the catalytic converter reaches its required working temperature.
  • Proven safe and effective by the Pros, now available in North America. TUV certified, made in Germany

Maybe, you remember the emission scandal with Volkswagen, which occurred in 2015 in Europe. The case dealt with the brand’s fraud concerning emissions testing for VW plus Audi automobiles. Their fraud caused a real scandal in European society and led to more severe regulations regarding air quality and emissions.

This Oxicat product was created in Germany and was initially meant for European drivers, who need to make their vehicles fit the new emissions rules. It’s a really efficient catalytic converter cleaner.

The creators of this item aspired to create a product able to clean not only the catalytic converter but also other details of the exhaust system, including oxygen sensors. It sounds good as, sometimes, malfunction of this sensor may lead to false information. Consequently, you may spend time and money on repairing a functional catalytic converter.

Besides, one more advantage is that it can be applied to various engine types, including diesel and hybrid ones. Undoubtedly, Oxicat offers products of top quality, which really work. Of course, the price isn’t the cheapest one for a small 10-ounce bottle, but almost everyone stays satisfied with this catalytic converter cleaner. No multipack options are possible.


Hi-Gear HG3270e EZ Emissions Pass & Catalytic Converter Cleaner

Hi-Gear HG3270s EZ Emissions Pass and Catalytic Converter Cleaner - 15 fl. oz.
213 Reviews
Hi-Gear HG3270s EZ Emissions Pass and Catalytic Converter Cleaner - 15 fl. oz.
  • Cleans fuel system, injectors, combustion chamber, pistons and valves
  • Restores lost horsepower and increases fuel efficiency
  • Prevents rotten egg smell
  • Reduces toxic gases and CO2 emissions
  • Removes carbon deposits

This product, sold in a metal tin, works exactly as the brand advertises on the package. It can cope with horsepower reduction, improve the vehicle’s performance, and reduce noxious gas emissions.

The main disadvantage is that this Hi-Gear item is applicable for gas engines only, and no cross-compatibility is possible. The efficiency of this catalytic converter cleaner is ensured by a specified formula, created as a joint venture of the brand and a range of auto manufacturers. Actually, it’s not an OEM product. However, its efficiency proves to be on a good level.

Multipack options aren’t available for this item. Thus, you need to buy one tin, pour it into the tank, and perform its functions. No more actions from you are required. As this item performs its duties properly and is easy to use, it definitely costs money spent on it.


Catalytic Converter Cleaner Solder-It CAT-1

Solder-It (CAT-1) Catalytic Converter Cleaner - 16 oz.
518 Reviews
Solder-It (CAT-1) Catalytic Converter Cleaner - 16 oz.
  • Helps eliminate "rotten egg" odor
  • May help in passing emissions control test!
  • Helps clean oxygen sensor
  • Extends time between tune-ups

This Solder product is another efficient but still rather pricy catalytic converter cleaner. In addition, it’s able to clean the vehicle’s fuel and exhaust systems.

It’s a great solution for gas motors, able to purify a catalytic converter no matter what type it’s off. It will cope even with monolithic and pelleted variations. Additionally, it can be utilized for oxygen sensor cleanup.

Serving as a deodorizer, CAT-1 will help you to get rid of the bad odour from the exhaust system, often compared to the smell of a rotten egg. However, bear in mind that you must be careful using it as this cleaner can be harmful to people.

The manufacturer claims that this product will make the car emissions fit all the regulations and pass through the emission control test. However, the producers of cheaper analogs provide the same guarantees.


About Sea Foam SF-16 Motor Treatment

Sea Foam SF-16 Motor Treatment - 16 oz.
15,323 Reviews
Sea Foam SF-16 Motor Treatment - 16 oz.
  • The product is sf16 16oz motor tune up
  • Easy and simple use kit
  • 100 percent pure petroleum
  • Pea registered product
  • Liquefies gum and varnish deposits or internal engine contaminants

The SF-16 product is new and ready to take on the tough jobs that come with owning a vehicle. This easy and simple cleaning solution liquefies deposits or internal engine contaminants, making it easier for you to change your oil! A friendly reminder: all items cannot be returned (only if damaged).

Sea Foam treatments are marketed as a solution for catalytic converter issues. However, the mixture of petroleum and alkylate only treat underlying problems in your engine that cause it to clog up in the first place.

Plus, Sea Foam doesn’t clean fuel injectors or combustion chamber at all. A true catalytic converter cleaner actually gives these parts a good cleaning. However, many brands will state they do so when it is not true.

Nonetheless, many individuals have experienced a fuel system fault code disappear after use.


Why Use Catalytic Converter Cleaners?

You may wonder what you need catalytic converter cleaners for. Here are four main reasons to invest in such a product.

  1. To get rid of odors. Some vehicles may release a very unpleasant odor, resembling the one of a rotten egg. That smell is a result of contamination of the exhaust system. And it’s accompanied by non-efficient filtering of the unburnt fuel from the exhaust stream. By cleaning the converter, you will fight that awful odor as converter cleaners perform the deodorizing functions.
  2. To increase performance.  A blocked catalytic converter often leads to reduced engine performance. The power reduction is extremely noticeable while driving on an incline or starting the automobile from a dead stop. This is a consequence of a blocked cat converter, which restricts the exhaust gas flow plus makes ventilation less efficient. As a result, the motor output suffers because of backing up with unvented gases. The common mistake is to replace a catalytic converter. However, don’t hurry to do that. In the majority of cases, the problem can be solved by simply cleaning the converter.
  3. To save money. We all know that replacing engine details is rather a costly issue, especially when we talk about catalytic converters. In addition to acquiring it, you will also need to pay a mechanic for placing it. Actually, there is no need to acquire new details if you can clean the ones, preventing your car from properly functioning. Therefore, by cleaning the catalytic converter, you will improve your vehicle’s performance and achieve the best fuel economy. Moreover, you will save money by regular maintenance rather than buying new details. Thus, by cleaning your cat converter regularly, you will avoid its unnecessary replacement.
  4. To achieve a low emissions level. As catalytic converters are designed to filter exhaust gases and improve air quality, by keeping your catalytic converter in order, you will take care of the atmosphere and people around you. We all know that the air is rather polluted, especially in urban areas. By reducing the level of emissions your vehicle produces, you will save the planet and take care of your and other people’s health. It’s a fact that today, the quality of air in the United States is 70% better than it was fifty years ago. As a result, fewer people are ill with asthma and several other diseases provoked by concentrated exhaust gases. Bear in mind that a clean catalytic converter functions more efficiently.


What’s the Lifespan of Catalytic Converters?

Usually, a catalytic converter serves pretty long. It will surely allow you to drive for 100,000 miles and more without facing problems with it.

A converter may serve long as its malfunctions are rather uncommon. However, if you had to replace the initial one, be sure that several years of trouble-free driving are guaranteed.

Moreover, it’s possible to avoid cat converter replacement if proper service is provided for the fuel system. By cleaning the converter regularly, you will increase its functionality and increase the lifespan.


How to Identify a Bad Catalytic Converter?

These are the main signs of a defective/clogged catalytic converter:

  • Rotten egg smell from exhaust. One of the telltale signs that a catalytic converter is going bad is if you smell something along the lines of rotten eggs. Gasoline contains sulfur, which turns into hydrogen sulfide in combustion at an engine’s high temperature. A working catalytic converter converts this smelly gas to odorless sulfur dioxide during the process. When the cat stops working due to its getting old or severely restricting airflow, some of these unburnt gases containing smelly hydrogen sulfides exit your exhaust channel.
  • “Check Engine Light”. It’s imperative to diagnose the problem as soon as possible and purchase catalytic converter cleaners because if your vehicle’s catalytic converter is failing or has gone bad, the “Check Engine Light” will illuminate on the dashboard. Such problems can usually be diagnosed and fixed by reading error codes from the car’s computer using a diagnostic tool. Common trouble codes include P0420 or P0430, which indicate that a catalytic converter has failed. Modern vehicles contain oxygen sensors that are able to monitor the catalytic converter’s efficiency by checking the exhaust’s gas levels if these sensors detect that there is something wrong with the efficiency of your catalytic converter then they will necessarily sense it via monitoring how efficiently your exhaust gases have been catalized.
  • Speed limit – when you struggle to drive more than 50-60 mph on a freeway (and there is no “check engine light’, or any other codes on transmission);
  • Black smoke from the exhaust;
  • Engine RPM is jumping;
  • The extra hot temperature under the vehicle.

To test if it’s really a clogged catalytic converter problem, you can disconnect it (release bolts) from the engine and check if your ride becomes much faster.



If you have decided to clean the catalytic converter and seek the best product, this review will be a great assistant to you. By choosing the proper product, you will achieve a desirable result easily and fast.

You will improve the engine performance and simultaneously lower the level of emissions it produces. Additionally, some cleaners may help to improve fuel efficiency.


Catalyst Cleaner FAQ

Where to buy catalytic converter cleaner?

You can buy catalytic converter cleaner by using links on our site or just go to the nearest auto shop.

Catalytic converter cleaner does it work?

Yes. This is proven by many reviews from car enthusiasts. The main thing is to choose a cleaner that is right for your occasion.

What is the best catalytic converter cleaner?

Mr. Gasket Cataclean is the best catalytic converter cleaner.

How to use catalytic converter cleaner?

Step 1: Pour the entire contents of the bottle into the gas tank.
Step 2: Drive a car for 15-20 minutes
Step 3: Reset all errors from the monitor and fill up the gasoline to half the tank.

How do catalytic converter cleaner works?

The fuel system cleaner removes carbon and varnish deposits from the vehicle’s fuel system and, as a result, reduces emissions.

Catalytic converters once had a lifespan of three to five years. However, even with modern advances in technology the catalytic converter will need to be cleaned during its lifetime for it work at optimum capacity.

Clogged exhaust systems are an issue that need to be addressed early and often because they don't just affect your catalytic converter and have a long list of effects including decreased fuel efficiency, increased emission output, and more frequent breakdowns among other serious problems so getting the engine checked regularly is essential when you hear clatter or see black smoke coming from your tailpipe.

Last update on 2021-10-16 / Affiliate links / Images from Amazon Product Advertising API

Andrew Price

Andrew is our top-rated author since 2019. He's a big car enthusiast and customisation pro, who knows how to get more performance from your car. Ask your questions in comment box down below this article.

5 thoughts on “Best Catalytic Converter Cleaner

  1. 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.

  2. I had a check engine light on, which was a pretty significant bummer since I had to get an emissions test to renew my registration; in my state, a check engine light is an auto-fail on emissions tests. Bought an OBD meter (also a great investment), said it was a catalytic converter issue – I cleared the code multiple times, but it kept coming back. At the prospect of a $700+ repair/replacement, I decided to try Cataclean instead.

    I did it mostly by the instructions but also incorporated the recommendation of a commenter (may have been on a different website)
    – I put it in right before I got on the highway. It was about 9 pm, so it was mostly empty.
    – I got into the left lane, and continuously revved the engine to the highest RPM’s I could then let it settle down. Did that for about 20 miles.
    – When I got home, I used my OBD meter to clear my codes. Drove for about 50 miles before I went in to get the emissions test, passed with flying colours.

  3. I have been using Oxicat on my Altima for 3 years, and it really helps.

  4. Until the last moment, I only refueled with pure gasoline, did not fill in any cleaning additives (not counting the dehydrator for the gas tank). The other day I went into a car shop and saw an interesting jar – a catalytic converter cleaner. I have not used this before, and I decided to try it.

    Although the volume of the bottle is designed for 65 liters fuel tank, while my Mazda3 has only 55, it’s okay, I poured it all out. For our gasoline, the mixture is “stronger” – a heavy plus)) According to the manufacturer, it removes soot from the catalyst, etc., for better fuel combustion and sensor operation.

    I drove the first 100 km and saw a small difference appeared in the reaction to the gas pedal at the very beginning of pressing. As if it is gaining momentum easier… It is difficult to judge by consumption, as driving in different conditions around the city, there were traffic jams…The country road was about 40 km. Half the time I went with an air conditioner.

    I reset the readings on the dash when refueling, now the computer shows 7.5 liters per hundred (before it was 8.2)

  5. Mileage Honda Civic 282 thousand km. The catalyst is native. The stench came from the exhaust pipe. I made the fill according to the instructions. I rolled out almost the entire tank. After about 300 kilometers, the smell disappeared and the engine became more responsive.

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