The IAT uses the number 5 runner. and also your coolant temp sender is right by that area, the actual ECT is on the bank 1 side. but honestly i think ur referring to the IAT
^^So if I'm understanding you correctly, when bcmbcmbcm asked what is the sensor on the lower intake by the #5 runner that would be the ACT correct?
ACT is generally the reference for the sensor if it's in the intake (like stock on an aero fox).
If the sensor is in the inlet tubing (like on an SN95, Explorer, etc) then it's often called an IAT.
It all performs the same purpose.
Yep, in preparation for the upcoming standardization being pushed by SAE...Ford was using IAT nomenclature for the OBD-I SN95 Mustangs.