Liqui Moly Catalytic System Clean fuel additive 300 ml — clears soot, restores combustion efficiency

Liqui Moly Catalytic-System Clean 300 ml is a fuel-additive treatment that removes soot and deposits from the injection system, combustion chamber and catalytic converter to help restore cleaner combustion.

Designed for gasoline engines equipped with catalytic converters, this 300 ml formula mixes directly with fuel and works as a preventative maintenance treatment. When added to petrol, it loosens and dissolves carbon deposits and soot that can impair injector spray patterns and block catalyst passages. The manufacturer specifies that one bottle treats up to 70 liters of fuel and the effects can persist for around 2,000 km, making it a convenient service between professional cleanings.

How does this product protect the catalytic converter?

The blend contains detergents and dispersants that reduce soot buildup, which helps keep the catalyst passages clearer and maintain exhaust flow. By minimizing clogging, it reduces the risk of premature catalyst degradation and helps stabilize backpressure in the exhaust system.

• Breaks down soot deposits on the catalyst surface
• Helps keep exhaust passages from becoming constricted
• Compatible with turbochargers and catalytic converter systems

Will it actually clean the fuel injection and combustion chamber?

Yes — the formulation targets injectors and combustion chamber deposits to improve spray pattern and combustion efficiency. Cleaner injectors and chambers support more complete fuel burn, which can lead to smoother idling and more consistent performance.

• Dissolves varnish and carbon on injector nozzles
• Removes combustion chamber carbon layers that impair compression and ignition
• Mixes automatically with petrol when added to the tank

How do I use it and how long does the effect last?

Pour the 300 ml bottle into up to 70 liters of petrol before filling or during refueling; it mixes automatically with the fuel. The product is intended as a preventative treatment and the beneficial effects are typically noticeable for up to 2,000 km, depending on driving and engine condition.

• One bottle treats up to 70 L of gasoline
• Add at any time — mixing occurs in the tank
• Effect duration around 2,000 km under normal conditions

Is it suitable for my vehicle and are there any precautions?

This cleaner is formulated for all petrol engines fitted with catalytic converters and is safe for use with turbochargers. Standard precautions for fuel additives apply: follow dosing instructions, avoid contact with eyes and skin, and store away from direct heat.

• Intended for gasoline engines with catalytic converters
• Tested safe for turbocharged engines
• Follow manufacturer dosing and safety guidance

Who is this for? Liqui Moly Catalytic-System Clean 300 ml is aimed at motorists who want an easy preventive measure to reduce soot and carbon buildup between service visits. It’s useful for drivers noticing mild performance irregularities, those wanting to protect a catalytic converter, or anyone who prefers proactive fuel-system upkeep without immediate workshop intervention.