2003 Ford Escape XLT runs strong but stalls while driving then 15/20 starts ok.

Hello, I would suggest checking for fuel pressure and for any signs of air intake issues or vacuum leaks. A vacuum leak could cause excessive air in the engine without controls, and the fuel may not keep up, plus this could possibly set a lean code for engine performance also. Testing is the only way to determine the cause of your problem properly.

Try cleaning the mass airflow sensor, a valve located in that big plastic thing by the air cleaner. My 2003 was doing the same thing and I sprayed a bunch of airflow cleaner on it, wiped it down with a microfiber cloth (as much as I could reach) and the problem went away immediately. What was happening is that it would warp ever so slightly during hot driving and then stick, especially at idle after freeway driving. Maybe not your issue, but doesn't hurt to clean the thing.

It could also be a Motor Electronics coolant pump. When the outside temperature heats up and affects the inner electronics, at high temp. The electronics system pump shuts down and waits until it cools down. Have it checked by a certified mechanic.