Ran a quick scan check with the car still idling after the 1.4 mile trip from the gas station. 14 counts of knock... and my IAT read about 26*, lowered to 21* when I opened the hood to make sure it was connected properly and still seated in the filter. I do have a Series II IAT, cause it'* smaller in diameter and longer, so it reaches into airflow better. Last time I checked, it was reading normal temps. O2 was showing lean most the time idling, flipped to rich momentarily a few times as I was looking.

Ever happen to anyone else? Will IAT'* go read wrong, but still function?

I could see the sensor itself being different and handing off different ohms etc which would equate to different temps at the PCM.

For example The temp is 30 degrees entering the airbox the S1 IAT provides 50ohm signal and the PCM interprets that as 30 degrees and S2 IAT provides a 70ohm signal that is interpreted as 40 degrees by the S1 pcm.but would be be 30 degrees to an S2 pcm.

Hmm, it'* reading correct this morning...

Double check the connections ...ensure they are clean.

Watched it on the way home, seemed fine till it dropped during a WOT run to -32*, that'* right, NEGATIVE 32*. Eventually, it came back up to 59, which was still low. Ambient was about 72. Fiddled with it when I got home and readings went back up to normal. I'm trying to reason why a wiring issue would cause weird readings like that. I'm thinking it'* the sensor.

I believe that they use a thermistor for the IAT, which are generally quite reliable. They do occasionally go bad, and when I was doing electronics sevicing, when they went, they could cause rather wierd readings. I think I'd swap it out.