RT did not eat his Wheaties. That is your MAT sensor (manifold air temp). Intake air temp is in the air cleaner box in the bottom. They use another sensor to measure air temp in the turbo's compressor manifold as the air gets heated up by the turbo.
In the picture it says only Econolines have it. That is because that manual was printed in early 99. F series have it.
This is the sensor I fought four almost a year to be added to the PID list on AE along with the missing left front sensor. It can now be viewed on AaE Giotto.
IAT Intake air temp is used to determine the outside air temp to set the cold idle rpm and ebv system
MAT is manifold air pressure down stream of the turbo and it's hot compressed air, hot being hotter than ambient anyway and can get into the 100s of degrees. The PCM adjust fueling from this input.