Does Seafoam Clean Catalytic Converters?

Does Seafoam Clean Catalytic Converters

Last Updated on August 6, 2023 By Emma W. Thomas

Seafoam is not designed to clean catalytic converters. It is a fuel additive used to clean carbon deposits from internal engine parts. For catalytic converter issues, seek professional diagnosis and potential replacement if necessary.

Does Seafoam Clean Catalytic Converters?

Seafoam is a popular fuel additive that is claimed to have numerous benefits for different parts of a vehicle’s engine. One of the areas where Seafoam is often discussed as being effective is in cleaning catalytic converters. The catalytic converter plays a crucial role in reducing harmful emissions from your vehicle’s exhaust system. However, over time, it can become clogged with carbon deposits, leading to decreased performance and increased emissions. In this listicle, we will explore whether Seafoam is truly effective in cleaning catalytic converters.

  1. Understanding the Function of a Catalytic Converter:
    Before we dive into the efficacy of Seafoam in cleaning catalytic converters, it is important to understand the role of this crucial component. A catalytic converter contains a specially coated catalyst that facilitates chemical reactions to convert harmful gases like carbon monoxide, nitrogen oxides, and hydrocarbons into less harmful substances like carbon dioxide, nitrogen, and water vapor.
  2. Seafoam’s Mechanism of Action:
    Seafoam is primarily marketed as a fuel additive that claims to clean carbon deposits and gunk buildup in various parts of the engine, including the catalytic converter. It is said to work by breaking down carbon deposits, improving fuel combustion, and reducing harmful emissions.
  3. Mixed Reviews and Limited Scientific Evidence:
    When it comes to Seafoam’s effectiveness in cleaning catalytic converters, opinions are divided, and there is limited scientific evidence to support these claims. While some users report positive results after using Seafoam in their vehicles, others remain skeptical, stating that it may not have a significant impact on catalytic converter performance.
  4. Removing Carbon Deposits:
    Seafoam may have some effect in removing light carbon deposits from the surface of the catalytic converter. Its cleaning agents can potentially loosen and dissolve carbon buildup, allowing it to be expelled through the exhaust system. However, severely clogged converters may require professional cleaning or replacement, as Seafoam may not be potent enough to tackle heavy deposits.
  5. Preventative Maintenance:
    Where Seafoam can be more effective is in preventive maintenance. By incorporating Seafoam into your regular maintenance routine, you may help reduce the risk of carbon buildup and prolong the life of your catalytic converter. Regular use can help keep the exhaust system clean, prevent further carbon deposits, and potentially improve overall efficiency.
  6. Proper Usage:
    To use Seafoam on your catalytic converter effectively, it is recommended to add the product directly to the fuel tank. Follow the instructions provided by the manufacturer to ensure the correct dosage for your specific vehicle. As with any fuel additive, it’s always best to consult your vehicle’s owner manual or a trusted mechanic before using Seafoam.

In conclusion, while Seafoam may have some potential in cleaning catalytic converters, its effectiveness can vary depending on the condition and level of carbon deposits. While it may help maintain a cleaner exhaust system, it is essential to note that heavily clogged converters may require more intensive cleaning methods. Always exercise caution and consult with professionals for severe cases of catalytic converter issues.

Can Catalyst Poisoning Be Reversed?

Depending on the type of contaminant, catalyst poisoning can sometimes be reversed. Reversal is done by running the engine under a very heavy load for extended hours. Doing this increases the exhaust temperature and sublimes or vaporizes the contaminant, removing it from the catalytic surface. For lead contamination, it is hard to remove through this method due to its high boiling point. 

How Does Seafoam Work?

Many things work together in your car’s engine to make it possible for you to drive your car around. Over time, the engine’s internal parts may get clogged up, thus reducing the engine’s performance and life. Tar and varnish may build up on the crankcase parts such as the oil galleries, lifters, pistons, and rings. This buildup eventually lowers the engine’s ability to cool and lubricate itself. 

The buildup also occurs in the fuel systems and clogs the carburetor jets, intake valves, and pistons. This dramatically affects the engine’s breathing and can lead to hotspots in the case of carbon deposits on the valves or pistons. The hotspots cause detonations and lower the performance of your engine. You need to keep your engine clean to avoid such issues, and that is where Seafoam comes in.

Seafoam motor treatment has been around for decades and is one of the most influential and trusted treatments for engines. It is specially formulated to reliquefy carbon deposits, varnish, gum, and sludge from the engine’s hard parts for easier flushing out. Seafoam also lubricates moving parts in the fuel system. Continued use of ethanol additives in your engine leaves the seals dry and with a varnish, making it hard for the parts to be lubricated by oil. Removing the varnish brings the machine back to maximum performance.

Seafoam also absorbs water in the fuel tank allowing fuel to be burnt in the combustion chamber without issues.

How To Use Seafoam Motor Treatment For A Cleaner Fuel System

Seafoam can be used in any gasoline or diesel engine. The most common uses for seafoam motor treatment are in fuel, oil, and storage.

In Fuel

When added to fuel, Seafoam works to clean and lubricate passageways. This makes engines start easier and run smoother with more power. It also works to clean carburetors in gasoline engines and fuel injectors in both gasoline and diesel engines. Seafoam also cleans harmful deposits from intake valves, and combustion chamber areas, and lubricates upper cylinders.

One can treat 16 gallons of fuels, so half a can will do just great. In diesel engines, Seafoam will de-ice and add anti-gel properties. It also controls moisture and stabilizes the fuel in any engine.


1. Open the fuel tank lid

2. use a funnel and pour up to half the bottle into the fuel tank

In Oil

When added to an engine oil crankcase, seafoam motor treatment works to clean and liquefy heavier oil deposits. One can treats 16 quarts of oil, meaning you get two treatments in a can for most vehicles. For best results, ensure you add the treatment when you’re 1000 miles or less to the next oil change. Then add the rest after you’ve changed the oil. This makes harmful residues drain away when oil is changed. This second treatment will clean internal engine parts and prevent sludge and other dangerous oil formations.


  • 1. Remove the cap on the oil filler neck
  • 2. Add Seafoam into the oil tank just before or after an oil change 
  • 3. Pour 1 ounce of Seafoam per quart of oil into the engine; you can use half the bottle for each treatment
  • 4. Replace the cap and let Seafoam do the cleaning

Stabilize Fuel

When preparing engines for seasonal storage, seafoam motor treatment works as a stabilizer and keeps fuel fresh and prevents varnish or gum formation, and keeps passageways clean all the time. It also controls small amounts of moisture and helps preserve ignition vapors for engines to start easier.

How To Clean Catalytic Converters

Catalytic converters reduce pollution and carbon footprint drastically by turning exhaust emissions into less harmful compounds to us and the environment. With years of usage, catalytic converters get dirty, and they need to be cleaned for your car to work in optimal condition.

When your car’s catalytic converter is dirty or clogged up with carbon deposits, it will show symptoms. These symptoms include:

  • 1. P0420 error code that says the vehicle’s computer is detecting a catalytic converter issue
  • 2. Emission of black exhaust smoke and fumes that smell like a rotten egg
  • 3. Reduced acceleration and engine performance
  • 4. High temperatures under the vehicle

Cleaning the catalytic converter will clear the symptoms as well as the error code. You can clean the converter either by removing it or without removing it. 

How To Clean The Catalytic Converter Without Removing It

Our first method of cleaning your catalytic converter is easy and cheap. You won’t need to get dirty, and you get to clean even your oxygen sensors and fuel plus exhaust system. For this method, you need to ensure there are no broken components or sediments in your converter. To check for damaged parts, tap your converter with a wrench. Ensure you hit it hard enough to rattle it but not hard enough to dent it. If you hear any rattling sounds on the inside, you may have broken components that can only be cleaned by removing the converter. If you don’t hear any noise, you can proceed with this method.

  • 1. For this method, you will need a catalytic converter cleaner and fuel
  • 2. Consult with your mechanic for the best quality catalytic converter cleaner that is compatible with your vehicle
  • 3. Read instructions on your chosen cleaner regarding the amount of fuel you should have and the quantity to use
  • 4. Pour the recommended amount of cleanser into your fuel tank
  • 5. Take a drive to ensure cleaner circulates, thus cleaning your exhaust system
  • 6. Drive with an RPM of 3000 and above to get the converter hot enough to burn out any residue or clogs

If you have a manual car, drive one gear a bit longer before shifting to the next gear. If you have an automatic transmission, drive in sport mode, or are equivalent in your car. Ensure you keep an eye on the temperature gauge to ensure it doesn’t overheat. To know if the cleaning process was successful, look out for the previous symptoms. You should expect less exhaust smoke, faster acceleration, and lesser instances of engine misfires.

How To Clean Your Catalytic Converter By Removing It

In case your catalytic converter has sediments or broken components, you may need to remove it for better cleaning. You can also use this method if the first one doesn’t produce the desired results. For this process, you will need: 

  • 1. An impact wrench
  • 2. Automotive degreaser
  • 3. A large container for soaking the converter
  • 4. WD-40 or any suitable penetrating oil
  • 5. Floor jack
  • 6. Jack Stand
  • 7. Oxygen sensor wrench
  • 8. Pressure washer


  • Ensure the vehicles exhaust system has cooled down before you start
  • Jack the car and leave enough space for you to slide under with ease
  • Use jack stands to keep the vehicle in position
  • Use the oxygen sensor wrench to remove the oxygen sensors
  • Locate the converter and apply penetrating oil to its bolts to loosen them
  • If your catalytic converter is attached or welded to the turbo, we recommend getting a professional to clean it for you
  • After unscrewing the bolts, remove the converter and inspect it
  • If it has rattling pieces inside, it means the internal components are in pieces, and you need to replace your converter with a new one
  • If there’s no rattle, clean the surface, then use a pressure washer on low settings to clean the inside
  • After you’ve washed the inlet and outlet pipes, fill a container with a degreaser and hot water
  • Soak the converter in the solution for about an hour
  • Rinse the converter with a pressure washer on low settings and let it drain till dry
  • Once dry, reinstall it and the oxygen sensor, then take a test drive and see if the car improves

If your vehicle doesn’t improve after trying both methods, it’s unfortunate that you need a new catalytic converter. Replacing is expensive, but worth it since it makes your car efficient again.

Wrapping Up

 Seafoam motor treatment works excellent to ensure your engine, especially the catalytic converter, doesn’t clog or get dirty. Using it regularly can save you many trips to the mechanic and the need to have your converter cleaned. However, if you notice symptoms that your converter is already clogged, Seafoam cannot do much. You, therefore, need a catalytic converter cleaner or a manual cleanse. 

Thank you for passing by. We hope this post helps you restore your car to its efficient state.