The system overview of the Duratec 2.0L shows an outline picture of the ECU sensors, the device that I found mounted at the front of my Plus 4 is described it as the ambient air temperature sensor. I can't find any evidence of a temperature measurement in the inlet air flow, I have just checked through the Ford parts lists. There is no inlet air flow measurement as the engine load fueling is based on a MAP sensor. Not sure if you would need an accurate measurement of the actual temperature at the air intake, just use an ambient temperature measurement to add into the feed-forward calculation and let the O2 sensor feedback do the final trim.
