The warranty length requirement on emmision equipment by federal mandate should be in your information package somewhere. If not phone another dealer or a zone office if you find your dealer will not give you a satisfactory response to a simple question at their level. You are also the proof that to expect to find a diesel with 200 k at 30 years of age is reaching a little. People buy diesels to pour the miles on them when fairly new. There are exceptions of course but buyers should be very careful. Wonder if your odometer will be cranked back at some point by someone in the future. I suspect it still happens as the dollars are there.