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.
How to Check and Maintain Your Diesel Exhaust Fluid
If the diesel exhaust fluid has been stored in the vehicle over the past 12 months, the American Petroleum Institute recommends that it be drained and replaced.