I took my 2003 Expedition on a 550 mile trip last weekend. Cummins engine ran very good for the first 460 miles and then showed problems with power, etc. the last 90. Made it home OK but not at 65-70 mph very often.
I had replaced the Fleetguard fuel filter before the trip and took it off and sawed it in half. The filter media was decently clean.
The 2003 Expedition had 20,900 miles on it when we left for the trip.
After researching this forum and others, I started looking for the inline filter before the lift pump. Here is what I found:
I think that filter is this:
I will check with the local truck shops to see if they stock this filter.