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Rislone DEF Crystal Clean Diesel DEF & SCR Emissions System Cleaner Removes Crystal Deposits

Rislone said its DEF Crystal Clean Diesel DEF and SCR emissions system cleaner scrubs away crystal contaminants from the selective catalytic reduction (SCR) systems of diesel cars, trucks, and SUVs.

March 18, 2024
Rislone DEF Crystal Clean Diesel DEF & SCR Emissions System Cleaner Removes Crystal Deposits

Rislon said its New DEF Crystal Clean Diesel DEF and SCR emissions system removes crystal contaminants from the selective catalytic reduction (SCR) systems of diesel vehicles.

Photo: Rislone/Canva

3 min to read


Rislone has introduced its DEF Crystal Clean Diesel DEF and SCR emissions system cleaner. The company said the new product scrubs away crystal contaminants from the selective catalytic reduction (SCR) systems of diesel cars, trucks, and SUVs to cost-effectively restore power and performance.

Maintaining Proper SCR Functions Through Maintenance

Modern diesel vehicles are equipped with SCR systems to reduce exhaust pollutants and meet stringent diesel emissions standards. These systems inject diesel exhaust fluid (DEF) into the exhaust gas to convert harmful nitrogen oxides (NOx) into nitrogen and water.

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Like any vehicle system, Rislone said the SCR functions best with proper maintenance.

DEF can break down and evaporate, leaving behind white crystal deposits. As these crystals build up, they clog SCR system components, interfering with normal operation, increasing fuel consumption, and reducing engine power. This can cause the vehicle to operate in “limp mode,” where it drives slowly or not at all.

Preventing Crystal Deposits in SCR Systems

Diesel vehicles that are regularly driven at low speeds, with light loads, for short durations, or that make frequent stops are especially prone to developing white crystal deposits in their SCR systems.

Rislone said its DEF Crystal Clean (U.S. p/n 4784) is a proprietary blend of cleaning agents and surfactant detergents specifically designed to safely and effectively clean SCR systems. It’s also much more affordable, the company added, than spending thousands of dollars to replace contaminated components.

“In Europe and other parts of the world where many passenger vehicles run on diesel fuel, SCR maintenance is more familiar and routine than in North America,” says Clay Parks, Rislone vice president of development. “But many diesel vehicles here have reached an age where SCR malfunctions are increasingly plaguing owners. We dedicated years of research to develop an effective solution to help our customers avoid costly SCR repair bills.”

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Protecting the Entire SCR System

Rislone DEF Crystal Clean dissolves crystal deposits throughout the entire SCR system, including the tank, pump, heater, sender, lines, injector, decomposition tube/reactor and mixer. It clears P20EE and related OBD codes and restores SCR function.

Regular use every 5,000 miles keeps the system clean, helps prevent new crystals from forming, and improves the life of emissions components, according to Rislone.

Rislone DEF Crystal Clean works with all UREA DEF/ AdBlue fluids in vehicles with DOC catalytic converters, DPF particulate filters, SCR devices, ASC ammonia slip catalyst, and DEF/AdBlue systems. It will not void manufacturers’ new vehicle warranties, according to Rislone.

To use, pour DEF Crystal Clean into a mostly full DEF tank or add and top off with DEF. Cars and small SUVs use approximately a half bottle. Light trucks and full-size SUVs install a full bottle. Medium- and heavy-duty trucks use two bottles.


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