By my catalog at work (GM Parts) the MAF is the same 97-98 & then 99-03. the 99-03 is a GM# 19179715 (ACDelco #213-4337).

But if your car is a 02 GTX it may have a different one from SLP, if they ported the TB and used a difference one you would have to use the number on the MAF Sensor and cross it to match.

Factory one looks like this