2014 F-250, 60K+ miles......Was in Provo, UT on vacation and started getting a check engine light. Had a diesel shop read the codes and he told me it was exhaust sensors, so I took it to a local Provo Ford dealer for what I thought would be warranty work. They told me it was the NOX Sensor and that they were not covered by emissions warranty. So $900+ later I get my truck back. Almost $350 for sensor plus labor then they tell me I need to clean the entire system so I do not have other problems. All in all, parts, labor and cleaning, it gets to better than $900. Has anyone had the same problem? Why would something in the emissions system NOT be covered by warranty?