23 - Manifold Air Temp Circuit (Low Temp)

[bowtieman]

Does anyone know where this is located at?And if you know the part number.

 

[RmvBfrFlght]

You didn't mention the model year. In the '86-'87 cars it is located in the elbow that comes off the top of the air cleaner. If it is missing or unplugged that too will cause a code 23.

RemoveBeforeFlight

 

[OvaBoost]

This thread has some pics of what you're looking for on an '86-'87:

http://turbobuick.com/forums/threads/how-to-pull-codes.379785/#post-3043044

HTH,
Bill