A high-pressure metering pump for providing reductant in a single fluid engine exhaust dosing system, comprising: a solenoid for actuating a piston slidably received within an inner bore of a valve housing of the pump, the inner bore having a pressure chamber with an inlet check valve and an outlet check valve; and wherein movement of the piston causes high pressure reductant to be received at an atomizer of the system, the atomizer being disposed in a location to cause a maximum reduction of undesirable pollutant in the combustion gases of an engine.