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Is there an additive to clean an O2 sensor?

Yes, there are additives available that can help clean an oxygen (O2) sensor in your vehicle. O2 sensors are critical components that monitor the air-fuel ratio in your engine, and keeping them clean is important for maintaining optimal engine performance and fuel efficiency.

What is an O2 Sensor?

An O2 sensor is a device that measures the amount of oxygen in the exhaust gases of a vehicle's engine. It sends this information to the engine control unit (ECU), which then adjusts the air-fuel ratio to ensure efficient combustion. Over time, the O2 sensor can become fouled with deposits, which can affect its accuracy and lead to issues like poor fuel economy, increased emissions, and even engine damage.

Using Additives to Clean O2 Sensors

There are several additives available on the market that can help clean O2 sensors. These additives are typically added to the fuel tank and work by dissolving and removing the deposits that have built up on the sensor. Here's how to use them:

Choose the right additive: Look for an O2 sensor cleaner or fuel system cleaner that is specifically formulated to target O2 sensor deposits.

Follow the instructions: Read the instructions on the additive's packaging carefully and follow the recommended dosage and application instructions.

Run the engine: After adding the additive to the fuel tank, drive your vehicle for at least 30 minutes to allow the additive to circulate through the system and reach the O2 sensor.

Monitor the results: Check your vehicle's performance and emissions after using the additive. If the O2 sensor is still not functioning properly, you may need to replace it.

It's important to note that while additives can be effective in cleaning O2 sensors, they are not a permanent solution. If the sensor is severely damaged or worn out, it may need to be replaced. Regular maintenance and inspections can help prevent O2 sensor issues and ensure your vehicle's engine is running at its best.

Can seafoam clean O2 sensors?

No, Seafoam will not clean oxygen (O2) sensors, but it can help prevent them from getting dirty over time by cleaning other engine parts. Seafoam is designed to clean the engine's internal components, and when used regularly in the fuel, it can help reduce the unburned carbon buildup that can foul an O2 sensor.
You can watch this video to see how Seafoam is used to clean engine parts: 59sWHO_TEE_WHOYouTube · Jan 11, 2018
How Seafoam works

Cleaning other parts: Seafoam cleans carbon buildup, varnish, and other deposits from internal engine components like the intake valves and combustion chambers.
Preventative maintenance: By improving the overall engine's clean state, it helps reduce the amount of carbon that would otherwise pass through to the exhaust and deposit on the O2 sensor.
O2 sensor safe: Seafoam is formulated to be safe for O2 sensors and catalytic converters, meaning using it in the fuel tank will not damage these parts.

What Seafoam will not do

Clean a dirty sensor: It is not a "cleaner" for a dirty O2 sensor and won't fix a problem caused by a sensor that is already clogged with carbon.
Fix a failing sensor: O2 sensors have a limited lifespan, and if a sensor is failing, using Seafoam will not restore it to proper working condition. In this case, the sensor will need to be replaced.

Can you clean an O2 sensor to make it work again after?

You can try to clean an oxygen sensor, but it is often not a reliable or long-term solution, and many experts recommend replacing it instead. Cleaning might temporarily fix a sensor that is only lightly fouled with carbon soot, especially if the underlying issue causing the soot is resolved. However, damage to delicate internal components or a sensor that has failed from age or contamination (like silicone from a coolant leak) cannot be fixed by cleaning.
Why cleaning is often not recommended

Damage is possible: Oxygen sensors have delicate internal components that can be easily damaged by aggressive cleaning methods like wire brushes or harsh chemicals.
Limited effectiveness: The pores in the sensor are so small that liquid cleaners may not be able to penetrate and clean them effectively.
Labor cost: If you have to remove the sensor to clean it, the labor is the same as if you were replacing it.
Risk of recurrence: If the cleaning is successful, the issue may return because the sensor can become dirty again, especially if the root cause of the contamination isn't addressed.

If you decide to try cleaning

Remove the sensor: The most effective methods involve removing the sensor from the exhaust pipe.
Use a specialized cleaner or method: Some people attempt to clean the sensor with carburetor cleaner or by burning off deposits with a propane torch, but this can be risky and damage the sensor.
Address the root cause: The most important step is to fix any underlying problem that caused the sensor to become dirty in the first place, such as a rich fuel mixture.

The most reliable solution

Replace the sensor: For a guaranteed fix and reliable performance, replacing the oxygen sensor is the best and most recommended option.

What additive cleans oxygen sensors?

Cataclean is a patented fuel and exhaust system cleaner that reduces carbon build-up and also cleans your vehicle s oxygen sensors, fuel injectors and cylinder heads. Cataclean does not alter fuel composition and is safe for gasoline, diesel and hybrid engines.

Will catalytic converter cleaner clean an O2 sensor?

Yes, many catalytic converter cleaners are designed to clean the O2 sensor as well by dissolving carbon buildup in the entire exhaust system. Products that use a fuel additive or an acidic vapor can clean pre- and post-combustion, which includes both the catalytic converter and the oxygen sensor.
This video explains how to clean your oxygen sensor: 1mPro Auto TipsYouTube · Jan 24, 2025
How it works

Fuel Additive: When added to the fuel tank, the cleaner travels through the fuel system, cleaning components like fuel injectors before it is combusted.
Acidic Vapor: After the fuel is combusted, the cleaner creates an acidic vapor that travels through the exhaust system, cleaning the catalytic converter, EGR valve, and oxygen sensors.

Important considerations

Damage: Only use products that are specifically labeled as "oxygen sensor safe" to avoid damaging the sensor.
Effectiveness: The effectiveness depends on the product and the severity of the clog. It is designed to clean buildup, not repair a physically damaged or worn-out sensor.
Maintenance: Regular use can help prevent future buildup that causes poor performance, reduced fuel economy, and failed emissions tests.

This video explains why you should not clean your oxygen sensor: 51sSUV Test LabYouTube · Nov 4, 2025

Kevin Bennett

Company Owner

Kevin Bennet is the founder and owner of Kevin's Autos, a leading automotive service provider in Australia. With a deep commitment to customer satisfaction and years of industry expertise, Kevin uses his blog to answer the most common questions posed by his customers. From maintenance tips to troubleshooting advice, Kevin's articles are designed to empower drivers with the knowledge they need to keep their vehicles running smoothly and safely.