Might want to clear any (if any) codes.Then the first code is the fault and the rest are reflecting what the first one is doing.Might want to consider the temp sensor.The EGR does create bad idle conditions,but when carbon build up is present,it should be consistent no matter what temps.Thinking out loud that is true until what ever carbon was holding it open was cleared.To clean that is alittle labor on your part and a help section from your local parts store screen gasket for only $8.00.