Sure you're not thinking of coolant temp spark correction? In my PCM_EE definition file version BZ, in TunerCat, I see no tables including IAT--only coolant temp.

 

Is that an OBDI file? Mine's OBDII, maybe that's the difference.
I definitely have a "Spark advance correction vs IAT vs MAP" table in there.

 

Is there a way to test to see what it is really reading? 10 year old sensor may not be working as good as it was new?

 

The temp sensor is a thermistor... the resistance varies inversely with temperature. With the harness connector removed, measure the resistance, and see if it is close to the value in the table of resistance vs. temp (for the actual ambient air temp). I think Shoebox has the table on his "how to test the sensor" writeup. If not, I have the table in my online scanner writeup:

http://members.aol.com/InjuneerZZ/ScanMast.htm

If you pull the sensor out, put it in ice water and see if it reads about 9,420 ohms, then put it in boiling water and see if it reads about 177 ohms (sea level only, at higher altitudes it will read a bit higher).

 

Either that's it or TunerCat hasn't added the table in the OBDI definition yet. Interesting!

 

Thanks a bunch...