2004 Ford Freestar and it sputters around 40 mph you have changed the fuel filter and had the fuel injection cleaned what could be causing this?

If your 2004 Ford Freestar is sputtering at around 40 mph despite changing the fuel filter and cleaning the fuel injectors, potential causes could include a failing fuel pump, a clogged catalytic converter, or ignition system issues such as worn spark plugs or faulty ignition coils. Additionally, check for vacuum leaks or issues with the mass air flow sensor, as these can also affect engine performance. A diagnostic scan can help identify any error codes that may point to the underlying issue.