Well I may have finally got some resolution, time will tell. The dealer that was sent by the district service rep brought my tractor back this evening. He replaced the EGR valve and new fuel filter. The service rep thought the first dealer I carried it to had just cleaned the EGR valve instead of replacing it like they had assured me they had done. Also said they broke open the fuel strainer. The dealer that brought it back this evening said that they had not touched it. One bad dealer has caused all this trouble. Glad it is up and running, feeling very relieved.