Your Mustang's manifold absolute pressure sensor or MAP sensor is located behind the firewall and provides manifold vacuum readings to the PCM. Make sure yours is in perfect working order with a replacement sensor from Latemodel Restoration Supply.
2003 Ford Lightning F-150
5.4 L TRITON V8 Engine w/ Eaton 8psi Supercharger
4R100 Transmission w/ LSD
4,670 lbs (empty)
Power estimated from Livewire Tuner (390 Hp, 470 Ft/Tq)
0-60 in 6.7 Seconds...