I've read various threads that mention having a clean IAT Sensor to ensure good milage. As I've never gotten more than 19 and more regularly get 18 on the highway (65-70), I'm looking at pulliing my IAT and taking a look.

Where is it on the '03?

 

The MAP and IAT are in combination on the intake manifold/plenum cover plate.
Its called a "combo" sensor.

 

Be careful not to confuse the "combo" sensor with the "combo" sensor on the airbox. They are similar but different.

 

my o5 has a ruff idle when it gets warm almost like a skip but it runs fine when it is cold .it also runs fine when im on it .so i dont think its an injector.but if you put it at 2k in nuetral and let off .it stays for 2 seconds and sputers down.ithink it is afualty sensor but where to start i dont feel like laying it up at the dealer any help much appreciated.