As with the smaller models, the KDI 3404 uses high-pressure common rail fuel injection, four valves per cylinder and solenoid injectors. It also has exhaust gas recirculation (EGR) as part of an emissions package that includes a Diesel Oxidation Catalyst (DOC) and Selective Catalytic Reduction (SCR) in a single exhaust unit, yet does without a Diesel Particulate Filter (DPF).
Kohler CEO Vicenzo Perrone says the engine is also ready for the move to Stage V in 2019, with the addition of a compact DPF within the same one-box exhaust system. The existing all-in-one module can simply be replaced with the new exhaust box, making it easy for equipment manufacturers to make the change to the new emissions regulation.