Why does it make a loud popping noise like a air riffle and it won't go over 25mph and it sounds like a motorcycle and smells like exhaust
Possibly a spark plug has blown out of the cylinder head. Check to see that all spark plugs are properly installed.
Ok someone said exhaust manifold
Could be that also, but exhaust manifold won't keep it from going faster than 25 mph.
Looking for a Used Expedition in your area?
CarGurus has 24,762 nationwide Expedition listings starting at $1,500.
Search Ford Expedition Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Ford Expedition Experts