Why f 150 idles smooth but at high speed or under load lacks power?

If an F-150 idles smoothly but lacks power at high speeds or under load, it could be due to several factors. Potential issues include a clogged fuel filter, faulty fuel pump, or issues with the ignition system, such as worn spark plugs or bad ignition coils. Additionally, a malfunctioning mass airflow sensor or exhaust restrictions could also impact performance under load. It's advisable to perform a diagnostic check to pinpoint the exact cause.