My car uses the MAT sensor to determine when to turn on EGR.
Do you have an '86 Vette or a '90-'91??
My '88 GM Shop manual states that code 32 will be set if the EGR valve is detected closed under the following condtions:
-coolant temp > 176 deg F
-EGR duty cycle commanded is >75%
-TPS <1/2 throttle & >idle
-codes 21,22,33,34 not present
-all conditions above met for >4 minutes
It further states that: "The (EGR) duty cycle is determined by the ECM based on information from the coolant and mass air flow sensors and engine RPM.