volvo def system
Volvoâs Selective Catalytic Reduction (SCR) system is a superior solution to the EPAâs emissions standards, not to mention a fuel- and cost-saving innovation for your fleet. Hereâs how it works: high-NOx/particulate exhaust flows from the engine to Volvoâs diesel particulate filter (DPF), where much of the exhaustâs particulate is removed. Next, before the exhaust reaches the catalytic converter, diesel exhaust fluid (DEF) is mixed in.