Catalytic converters are essential for reducing harmful vehicle emissions, but over time they can become clogged with carbon deposits and soot. As this buildup increases, the converter’s efficiency drops, leading to a noticeable decline in vehicle performance. Drivers may experience rough idling, reduced throttle response, poor fuel economy, and even a sulfur-like odor from the exhaust. Eventually, the check-engine light may come on, and passing an emissions test becomes more difficult.

In severe cases, a clogged catalytic converter—sometimes one of two in a modern vehicle—may require replacement. Unfortunately, these emissions-critical components can’t typically be repaired, and replacement costs often run into the hundreds of dollars.

Fortunately, there’s an effective, low-cost solution that can help prevent this kind of damage: Cataclean. Developed in the UK and distributed exclusively in North America by Holley Performance Brands, Cataclean is a one-step, pour-in treatment designed to clean both the fuel and exhaust systems. Used regularly, it can help maintain engine efficiency and extend the life of your catalytic converter, oxygen sensors, and diesel particulate filter (DPF), where equipped.

How Cataclean Works

Using Cataclean is simple. Pour the contents of the pre-measured bottle into approximately a quarter tank of fuel (about 4 gallons or 15 liters), drive for at least 15 minutes to bring the engine and exhaust system up to temperature, and then refuel as normal.

What sets Cataclean apart from other products is that it works on both sides of the combustion process—before and after. Its active ingredients include acetone, isopropanol, xylene, and kerosene—all proven safe for internal combustion engines, whether gasoline, diesel, or a hybrid design.

Once added to fuel, the solvents begin dissolving gum and varnish in the fuel system. As the mixture is drawn into the engine, it cleans dirty fuel injectors, intake valves, and combustion chambers—areas where deposits often cause rough running, reduced performance, and increased fuel consumption. By cleaning these areas, Cataclean helps restore combustion efficiency and power.

“Whenever you clean up the deposits from anywhere in your engine or fuel system, you always pick up performance,” says Doug Wright, Director of Cataclean Business Development for Holley.

Post-Combustion Benefits

After combustion, Cataclean continues its job in the exhaust stream. It targets catalytic converters, oxygen sensors, and DPFs, helping to remove carbon and soot that accumulate over time. The combustion byproducts of Cataclean generate oxygen to help oxidize carbon deposits and release a vapor containing carboxylic acids, which assist in breaking down and flushing out soot.

The result is a cleaner exhaust system, improved emissions, and better overall engine function.

What Cataclean Can—and Can’t—Do

A compromised catalytic converter can sometimes result in DTC engine codes. Some of the more common include P0420 or P0430 for below system threshold, P0171 or P0174 for lean condition, P0300 for random misfire, and P0401 for insufficient EGR flow. Cataclean can deter these DTC engine codes from popping up by keeping the converter clean and running smooth. It can also help clear some of these codes.

It’s important to note that Cataclean can’t reverse damage to components that are already beyond recovery. If your check-engine light remains on after treatment, or if your converter is already fully clogged, replacement may still be necessary. However, routine use of Cataclean—about four times a year—is recommended to prevent this level of buildup from happening in the first place. Each treatment typically costs less than $30, making it an affordable option compared to major repairs.

Ideal for City and Short-Trip Drivers

Vehicles that make frequent short trips—like those used in city driving—are especially prone to carbon buildup. Without enough time at highway speeds, exhaust systems don’t reach the high temperatures needed to burn off deposits naturally. This puts components like EGR systems, DPFs, and catalytic converters at higher risk of being compromised.

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Fleet operators in the UK have seen impressive results using Cataclean on their stop-start delivery vans. In one independent test, a commercial van fleet saw emissions drop by 24% and DPF performance improve by 27%. Fuel consumption dropped nearly 10%, making the treatment self-funding through fuel savings alone.

“Modern fuel and exhaust systems are designed to reduce emissions, but in real-life conditions, they get dirty,” explains William Jones, UK Sales Director for Cataclean. “That dirt can lead to breakdowns and lost productivity. Prevention is always better than cure.”

A Small Investment with Big Returns

Cleaner emissions mean more than just being eco-friendly. They reflect a more efficient engine, with better fuel economy and restored performance.

For drivers who want to protect their vehicle from costly repairs and keep performance sharp, Cataclean is an easy, affordable, and effective solution—especially when used as part of a regular maintenance schedule.