EuroV Aftertreatment SystemEuroV Aftertreatment SystemThe Selective Catalytic Reduction (SCR) catalyst converts a mixture of nitrogen oxides and Diesel Exhaust Fluid (DEF) into nitrogen and water. DEF is pressurized by a pump and is then sprayed into the SCR catalysts within the mixing chamber.. EuroV Aftertreatment System Aftertreatment Device Sensor Locations SCR Outlet NOx Sensor DEF Dosing Unit SCR Inlet NOx Sensor SCR Outlet Temperature Sensor SCR Inlet Temperature Sensor18-pin Electrical Connectors Exhaust Inlet Exhaust Outlet ACM Cover Parent topic: Aftertreatment System