While servicing a vehicle, you retrieve the diagnostic code P0401, "EGR (exhaust gas recirculatior flow insufficient." Which of these is the most likely cause?

An engine runs on the ideal diesel cycle. the cycle has a compression ratio of 20 and a cutoff ratio of 2. the highest temperature in the cycle is 1200 k. if the heat into the system is 300 kj/kg of working fluid and using variable specific heats determine the work produced per mass of working fluid