If the transmission does not shift from first to second gear, the vehicle will not be able to gain more speed. Normal shifting of the transmission is necessary for the truck to speed up. The transmission shift solenoid valve or the transmission range sensor may be bad. They are located inside the transmission. Have you checked the fluid? How many miles in the truck? I would change the fluid and filter first to see if this clears the problem.
Why don't you stick with your first question instead of posting the same question over and over?
still have warranty if so use it .IT WONT BE CHEAP FIX
Looking for a Used Expedition in your area?
CarGurus has 434 nationwide Expedition listings starting at $5,500.
Search Ford Expedition Questions
Ford Expedition Experts
Related Models For Sale
Used Cars for Sale