A catalytic deSoot-deNO(x) system, comprising Pt and Ce fuel additives, a Pt-impregnated wall-flow monolith soot filter and a vanadia-type monolithic NH3-SCR catalyst, was tested with a two-cylinder DI diesel engine. The soot removal efficiency of the filter was 98-99 mass% with a balance temperature (stationary pressure drop) of 315degreesC at an engine load of 55%. The NOx conversion ranged from 40 to 73%, at a NH3/NOx, molar ratio of 0.9. Both systems were measured at a GHSV of 52 0001/(1 h). The maximum NOx conversion was obtained at 400degreesC. The reason for the moderate deNO(x) performance is discussed. No deactivation was observed after 380 h time on stream. The NOx emission at high engine loads is around 15% lower than that of engines running without fuel additives.