The 3+ BEST Catalytic Converter Cleaners (Reviews) in 2021

Most vehicles, unless you have an electric car, come with a catalytic converter. The purpose of this component is to filter out toxic chemicals and compounds, like carbon monoxide, from the exhaust emissions.

Inside the converter these emissions are converted into gases so they aren’t as harmful to the environment when they leave the exhaust. During this process, it’s possible for the catalytic converter to get clogged.

When this happens, it’s not going to function properly, and will need to be thoroughly clean or repaired depending on the severity of the clog. To prevent this from happening, it’s a good idea to use a catalytic converter cleaner to keep this component operating smoothly.

In this post, we’ll look at the best catalytic converter cleaners that you can use to keep the exhaust system in your vehicle running in prime shape. We also put together an in-depth buying guide, some helpful tips, and an FAQ section to make things easier for you.

With that out of the way, let’s jump right into it!

The Best Catalytic Converter Cleaners

Cataclean Complete Engine Fuel and Exhaust System Cleaner (Best Catalytic Converter Cleaner Overall)

The Cataclean Complete Engine Fuel and Exhaust System Cleaner is our top recommendation as the best catalytic converter cleaning product for most people. This is a highly effective formula that’s designed to break down carbon deposits and reduce their build-up in your vehicle exhaust system.

There are a number of benefits to using this fuel system cleaner. For starters, it can help to restore the catalytic converter while cutting down vehicle emissions by up to 50%.

It’s also effective at restoring the oxygen sensors, fuel injectors, and cylinder heads. This makes it a great solution for running through the fuel system if you’re having any engine or fuel related problems.

It’s possible to use this product for both gasoline and diesel engines. It can even be used for hybrids, which makes it versatile and a practical choice regardless of the car you’re driving.

Using it is simple and only involves emptying the bottle into the partially filled gas tank. While the solution is in the fuel system it won’t alter the fuel in any way so the vehicle can maintain its peak performance.

This is an environmentally friendly catalytic converter cleaner and can be legally used in all 50 states. The chemicals and other ingredients comply with all of the federal low sulphur content regulations as well as the VOC regulations.

Only one concern is worth mentioning and it’s that this formula can’t be used for two stroke engines. Otherwise, it’s a great choice for most vehicles and we would definitely recommend using the Cataclean Complete Engine Fuel and Exhaust System Cleaner if you’re having trouble with the catalytic converter.

Solder-It Catalytic Converter Cleaner

The Solder-It Catalytic Converter Cleaner is a great option if you’re on a tight budget. This is a cost-effective solution for cleaning the fuel and exhaust system in your vehicle.

What most people seem to love about this cleaner is that it’s great for getting rid of the rotten egg smell. Since this is a symptom of a bad catalytic converter, it doesn’t hurt to run this through the fuel system to remove the stench.

This is a cleaning solution that’s particularly designed for gas engines and can be used for cleaning all types of catalytic converters. It’s also safe to use to clean the oxygen sensor if you think you’re having trouble with that.

Those of you with older or high-mileage vehicles that need to pass an emissions test should consider running this through the system. It can definitely help break down any clogs or carbon build up that are causing problems with admissions.

The only drawback to this cleaning product is that the bottle is rather small. This means you may need to use more than one bottle to run it through the entire fuel system.

Otherwise, the Solder-It Catalytic Converter Cleaner is a great choice to use as a cheap catalytic converter cleaner if you’re on a budget. It can be used with all types of converters and is ideal for gas vehicles.

Autoprofi OXICAT Cleaner

The Autoprofi OXICAT Cleaner can be used for effectively cleaning the oxygen sensors and catalytic converters on your vehicle. This is a cleaner that’s safe to use for all kinds of fuels, including gasoline, diesel, and hybrid vehicles with different fuel mixes.

Made in Germany, the Autoprofi OXICAT Cleaner promises both a high-quality and reliable fuel system cleanse. It was originally developed as a high-performance cleaner as can be used for effectively removing dirt, soot, and carbon deposits from the fuel and exhaust system.

Considering how easy this product is to use, especially with the bottle adapter for making it easier to get into the fuel system, there’s no reason not to use this product regularly. Using it every few months can really help improve emissions and keeping the vehicle running in prime shape.

When it comes to restoring engine performance and protecting the fuel system against heavy dirt, the Autoprofi OXICAT Cleaner is a great choice. Although there isn’t much product in the bottle, it’s more than enough to use for regular cleaning of the entire fuel system.

CRC Guaranteed to Pass Emissions Test Formula

Despite the interesting name, the CRC Guaranteed to Pass Emissions Test Formula can be effectively used for cleaning the catalytic converter. This product is unique because they’ll give you your money back if your vehicle doesn’t pass the emissions test.

As a catalytic converter cleaner, this product comes with a number of powerful detergent additives. This ensures that the entire fuel system is properly cleaned up for better emissions and a cleaner exhaust.

After running this through the system you will get a significant reduction in emissions as well as an overall increase in performance. While it’s not suitable to use for diesel engines, this is a great cleaner to run through your gas vehicles.

The company themselves recommends using this product every 3000 miles to keep the emission levels and fuel economy at top performance. It can be used with all different kinds of ethanol and gasoline blended fuels.

Considering how affordable and easy it is to use this product, there’s no reason not to use it on a regular basis. It will definitely help your engine pass the emissions test with powerful detergent additives that act quickly.

Overall, the CRC Guaranteed to Pass Emissions Test Formula is a great choice for restoring your car’s fuel system and significantly lowering emissions. While it can’t be used for diesel engines, it will work great on all gas powered vehicles.

Hi-Gear Fuel System Cleaner

The Hi-Gear Fuel System Cleaner is designed to clean the catalytic converter as well as the entire fuel system. This helps to improve fuel efficiency and keep things running smoothly, which saves you money in the long run.

After running it through the system, this cleaner is effective at cleaning the pistons, valves, fuel injectors, as well as the combustion chamber. All of this boosts the vehicle’s overall performance while getting you back any lost acceleration, horsepower, and hard starts.

You could use this to help manage any car backfiring problems for it to improve the fuel system. It will even help get rid of the rotten egg smell and lower emissions so it’s more likely for the vehicle to pass an emission test.

The only concern with this solution is that the bottle is rather small. For some vehicles, one bottle would be enough, but you may need to use additional bottles for bigger vehicles or heavy build ups.

Overall, the Hi-Gear Fuel System Cleaner is a great way to clean out the fuel system in your vehicle and get the catalytic converter running in prime shape. This can definitely increase fuel efficiency, remove carbon deposits, and restore lost horsepower and acceleration.

Why You Should Use a Catalytic Converter Cleaner

Better Engine Performance

One of the main reasons you should be using a catalytic converter cleaner on a regular basis is to keep your vehicle running in prime shape. It’s possible that a clogged or gunked up catalytic converter can be to blame for less performance from the engine.

Using one of these cleaners will help clean the fuel injection system, just like using a fuel injector cleaner. It will also help clean the cylinders and improve overall performance while reducing fuel consumption.

Lower Emission Levels

Although modern catalytic converters are pretty efficient at keeping harmful gases emitted from the exhaust to a minimum, some gases can still get through. Using these cleaners can further reduce the engines emission levels so it’s even less harmful for the environment.

Considering how easy they are to use, it’s a good idea to add this to your regular vehicle maintenance routine. This way you’ll know that the emission system is in better shape overall.

Save Money

Another benefit to maintaining better engine performance is that you save money with lower maintenance and fuel costs. These can be some of the biggest expenses of car ownership so it’s worth trying any improvements or preventive maintenance.

You also save money by not having to change or repair the catalytic converter as often or even at all. This can be a big, unnecessary expense if you’re not careful or if you avoid doing any maintenance as recommended.

Better Smells

Build up and clogs in the catalytic converter can possibly cause the vehicle to develop an unpleasant smell. This would present itself as the signature rotten egg smell that you may be familiar with.

If you notice your vehicle exhaust is starting to smell like this, it would be a good idea to use a catalytic converter cleaner. This would help break down any clogs and clean things out so the exhaust smells better.

Protect the Engine

Another benefit to regularly cleaning the catalytic converter is that it will help to protect your engine from damage. With the engine running smooth and cleaner text to proper fuel and exhaust flow, it will maintain a better performance.

This is a benefit that’s hard to overlook given how easy it is to clean this component. With so many different catalytic converter cleaning products available to choose from, there’s no excuse not to do this.

Pass Emission Tests

Depending on where you’re from, your vehicle may need to pass an emission test to get it on the road. For older vehicles, which typically have tricky emissions, using a catalytic converter cleaning treatment can improve the emissions.

These treatments help to break down clogs, old gunk, and other carbon-based build ups that get caught up in the fuel system. This leads to cleaner emissions so the vehicle can pass an emission test and get on the road.

How Much Does a Catalytic Converter Cleaner Cost?

Under $10

In this price range you’re looking at cheap catalytic converter cleaners that are ideal if you’re on a tight budget. The cleaning won’t be as good and it’s possible you could get stuck with a poor quality product that could do some damage.

Ideally, we would recommend spending a little more money to get a better quality, higher rated cleaner to use on your vehicle. This will also give you better peace of mind and should work more effectively at cleaning everything out.

$10 to $20

In this price range that are some good quality products that are suitable for getting the job done. Most of these will come with slightly different formulas that still end up doing the same thing.

Don’t forget that you’ll have to choose a specific formula depending on whether you’re driving a diesel, gas, or hybrid vehicle. It should be easy to find some reasonably priced and well-reviewed cleaners at the higher end of his price range.

Over $20

For this price range you’re looking at high-end catalytic converter cleaners from big name brands. It’s also possible to find multi-packs of them, which is a good choice if you’re doing multiple vehicles or cleaning this component regularly.

Ultimately, there isn’t any reason to spend more than $20 for a single bottle. You would only need to spend this much if you’re looking at a specialty formula or you’re set on a particular brand.

Key Features

Engine Compatibility

Most catalytic converter cleaning treatments will work on regular, gas-powered engines. Those of you with diesel or hybrid cars will want to check the compatibility of the cleaner to make sure it works for these particular vehicles.

With diesel and hybrid vehicles, a premium or specialty blend is typically needed. These are specialized engines and require different treatments for it to be effective.

Full System Cleaning

Some of the best cleaners are capable of cleaning the entire exhaust system, as opposed to just the catalytic converter. This means that the whole system can be given a good flush so that everything continues to function as intended.

These are especially a good idea for older cars or high-mileage vehicles where it’s important to keep everything running in prime shape. Otherwise, for newer vehicles for low-mileage ones, it wouldn’t hurt to use a specific product to clean everything out.


Some of the different catalytic converter cleaners come with additional detergent additives. You don’t really need these and can avoid these products if you’re looking to save money.

Especially for regular gas powered cars, there’s no need to use the fancy additives. Just the basic cleaner solutions are more than enough to get the job done.

Bottle Size

Something you might overlook when you’re checking out the different cleaners is the bottle size. The most common size is 16-ounces and this is what we recommend using.

Anything bigger is unnecessary since you won’t need to use that much cleaner to clean the exhaust system. There’s no point in keeping it either, since the opened bottle will immediately start losing potency while it’s stored and unused.


As you probably have already realized, these cleaning products are basically a bottle filled with chemicals. Along with being safe to use in your car, it should also be safe for the environment.

If this is something that’s important to you, check that the cleaning solution meets necessary regulations. Look for the VOT and OTC tags or information in the description so you can confirm that it’s an environmentally friendly product.

Helpful Tips

  • It’s recommended to use approximately one ounce of catalytic converter cleaner for every gallon of fuel. This is an easy formula to remember so it can be quickly adjusted depending on the size of your gas tank. It’s even possible to use this on smaller engines, including motorcycles.
  • There’s no need to have a full tank of gas to use one of these cleaning products. What’s more important is using as much of the gas tank as possible so that the cleaner can work its way through everything.
  • Older vehicles would see more benefit to using a catalytic converter cleaner more often. This is because they typically produce more harmful emissions compared to newer vehicles with less mileage.
  • After the catalytic converter cleaning solution makes its way through the system, fill up the gas tank completely. Then, drive at least 50 miles or so on the highway so that the onboard computer can recalibrate.
  • Start using one of these cleaners on your vehicle as soon as you can, especially if you have never used one before. This helps with regular catalytic converter maintenance to keep things running smoothly and to prevent any problems in the future.

How to Use a Catalytic Converter Cleaner

Step 1 – Check the Spark Plugs

The first thing you should do before running anything through the fuel system is to check the spark plugs. With excessive carbon buildup on the converter, your vehicle is likely running rich.

This means that the fuel and air mixture isn’t right or one of your spark plugs isn’t sparking correctly. It’s a good idea to change the spark plugs regularly to avoid this issue, with the information being available in your owner’s manual.

With good spark plugs there will be less carbon build up on the catalytic converter since all the available fuel will be burnt off. You can also refer to your owner’s manual to find out the type and amount of spark plugs you should buy.

Step 2 – Add the Cleaner

Assuming your spark plugs are new or in good shape, it’s time to use the cleaner. Start by measuring out the amount you need, opening the gas tank, and pouring the bottle inside.

Always read the instructions before using any of these cleaner products. This way you’ll know exactly how much to use and if there’s anything else you need to do.

Step 3 – Fill the Tank

After adding the cleaner, fill the gas tank. This is to help mix everything through and to recalibrate the onboard computer.

Alternatively, you could add the solution to a full gas tank. This would work as well if you’re in a pinch.

Step 4 – Drive the Vehicle Regularly Until Close to Empty

To make sure the cleaning solution cycles through the exhaust system, drive the vehicle until it’s close to empty. This way you can be sure it’s running through the catalytic converter and not just sitting in the fuel tank.

Step 5 – Check Engine Light

If the check engine light came on and you checked it with your OBD-2 scanner, you may have gotten a catalytic converter error code. After using the cleaning solution, you can reset the code if it’s related to the converter.

It’s easy to clear these codes if you’re using one of the check engine light scanners. Otherwise, it may automatically turn off or you should refer to the vehicles owners manual to see how to turn it off.

Step 6 – Refill the Gas Tank and You’re Done

At this point, most of the cleaner should have made its way through the exhaust system and shouldn’t be in the gas any longer. Go ahead and refill the gas tank and you should be good to go.

Make an effort to run the catalytic converter cleaner through the engine on a more regular basis. As recommended, it’s a good idea to do it every time you change the oil.

Frequently Asked Questions

How Do You Use a Catalytic Converter Cleaner?

Using any of these catalytic converter cleaners is a simple task and should be part of your routine vehicle maintenance. It’s as easy as pouring the bottle into the semi-full gas tank and then driving regularly until the tank is empty.

This ensures that all of the chemical cleaner makes its way through the system and gets used up. Don’t forget to fill up the tank afterwards so that the vehicle computer can recalibrate itself.

Can These Cleaners Be Used to Fix a Clogged Catalytic Converter?

The only way to completely fix a truly clogged catalytic converter is by replacing it. That’s why it’s recommended to use these cleaners regularly, especially if you have never used them before.

Before replacing it, it would be a good idea to bring your vehicle to the mechanic. This way they’ll be able to inspect the clog and see how bad things are to let you know if you can fix it.

How Does a Catalytic Converter Cleaner Work?

These cleaning solutions filter out and convert harmful compounds and gases that are in the exhaust into less harmful gases. Instead of harmful gases coming out of the exhaust, you’ll get carbon dioxide and nitrogen, which is less harmful for the environment.

What happens is that gunk and buildup can start accumulating in the catalytic converter. Most of this is carbon, which can be easily managed at the beginning.

All of these different cleaners use a liquid chemical formula that dissolves the build-up through chemical reactions. It’s easier and definitely more affordable this way than having to repair or replace any of these components.

How Often Should You Clean the Catalytic Components?

Most people overlook this component and some might never clean it. If you’re staying on top of your vehicle maintenance, it’s a good idea to clean the catalytic converter every 5,000 miles or so.

To make it easier to remember, clean it every time you do an oil change. This will make it become part of your preventive vehicle maintenance so you’re less likely to forget to do it every time.

Do Catalytic Converter Cleaners Work On All Vehicles?

Yes, these cleaners are safe to use with all vehicle makes and models. They can even be used on older cars and those with higher mileage.

Don’t forget that if you have a diesel or hybrid vehicle, you need to buy a cleaner that’s compatible with that particular engine. The overall efficiency depends on how much grime has accumulated within the converter and how often it has been cleaned.

Do Catalytic Converter Cleaners Actually Work?

Yes, of course they work, assuming you chose a high quality product. Most of the best catalytic converter cleaners will clean the converter as well as other components, including the fuel injectors, fuel system, and pistons.

It’s a good idea to look at reviews to see what other people have to say about the cleaning product you’re interested in. This way you’ll know if you’re getting something that works or if it’s a product you should avoid.

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