Code 23 MAT Sensor

[96RS Alex]

I need a little help again due to an unexpected slight rough idle I experienced today from my '91 Firebird 3.1 V6.
The orange SES light pops on whenever it's idling at long red lights and stays on until I shut it off. I went to Autozone for a waterpump today and asked for a free diagnostic scan and they extracted a Code 23. I was given a thorough print out sheet to help me troubleshoot the problem and I left too soon to ask what the MAT sensor would look like from their inventory and it's many miles away, I goofed.
I would like to replace this sensor before I tear it down for the waterpump so no codes can be throwing me off. Where is this sensor located?
I provided a link to see what Code 23 means. > http://www.4chevy.com/troubleshooting.htm

[Phoenix]

It screws into the air box, another name for it is the Intake Air Temperature sensor (IAT).

[96RS Alex]

Thanks, I found the sensor there after looking around the manifold area. Turned out to be corrosion in the contacts. Cleaned and no more codes.
Sensor is $25.99 at Autozone, it's small but didnt have to purchase one.