A method of reducing emissions from a diesel engine including the steps of providing an injector to an exhaust outlet of the diesel engine, the injector having an orifice with a diameter of about 0.006 inch or less, providing a reagent to the injector at an inlet pressure between about 120 psi and about 60 psi, actuating the injector on and off at a frequency between about 10 Hz and about 1 Hz with an on-time of about 1% or more, injecting the reagent via the orifice into the exhaust outlet at an injection rate, and wherein varying of at least two of the inlet pressure, the frequency, and the on-time achieves a turn-down ratio of a maximum injection rate to a minimum injection rate of at least about 31:1.