Ok I just had the same problem my car was in the shop for two weeks and nobody could figure out what it was I know what to do , if your odometer only have dashes then you have the same problem I had, What you have to do is change the fuse for your Hego that is a heated exhaust gas oxygen sensor fuse , look in your owners manual and check which fuse that is it should be located under the hood next to the battery in my case for my 02 Ford Explorer it was fuse number 41 but I'm not sure if it is the same as yours
RepairPal Certified shops can diagnose and repair your 2005 Ford Expedition. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.