Medium and heavy duty trucks manufactured starting on January 1, 2010 are required to meet the EPA Emission Standards. The majority of truck manufacturers chose to use selective catalytic reduction (SCR) technology to meet the standards. As part of SCR technology, Bosch provides the Denonxtronic 2.2 dosing system which injects urea into the exhaust which interacts with the SCR catalyst to reduce the NOx emissions level. The supply module contains a main filter which filters the urea being pumped into the dosing module. The filter needs to be replaced per the manufacturers’ scheduled maintenance requirements.