The computer doesn't control individual cylinders on a 9600, mainly the rack position and govenor. If you have more than 3000 hours I would first look for a bad injector.
Depending on hours on engine. Change all fuel filters, pull outer air filter, pop test injectors, adjust valves, check injection pump timing, be sure turbo isnt out and hasnt filled aftercooler with oil. Is it acting up on idle or WOT, with a load or withoutIJ