Aust fluids are vital to keeping your car’s health in good condition. In particular, it’s made up of water as well as Urea that goes into the exhaust system, and then goes through the exhaust pipe. This process turns potentially dangerous pollutants into fresh air.
The DEF fluid, as shown in the attached video will react through a filter the DEF dosing valve as well as an SCR. The acronym SCR is for selective catalytic reduced, that is a high-tech emission control system designed to reduce the emissions from tailpipes. After exhausting, the gas is passed through a filter and later into a wall flow filter. The carbon particles are found within the filter. Diesel oxidation catalyst transforms the exhaust gas to nitrogen oxide. The reason for this is that the nitrogen oxide reacts to the carbon and creates carbon dioxide. It is water vapor, but not harmful contaminants that are discharged from the tailpipes. This is the place where DEF fluids can play an important role.
The video linked above provides more details about DEF fluids and their uses.