The IAT sensor in a 2001 through 2005 Honda Civic EX is positioned on the intake manifold on the driver's side, directly under the throttle body/throttle position sensor. The IAT location varies depending on the model and year. For the 1998 Honda Civic, it is plugged in the intake manifold.
The 2007 Honda CRV has its IAT as part of the mass airflow sensor. It has a four-pin connector to the combined MAS/IAT, positioned on the throttle body housing. For the Honda Civic EX, it is necessary to open the hood and stand on the driver's side of the car, and then look at the throttle body directly to see the IAT connector immediately underneath.