1996 Gt With High Idle Problem

[1993cobra5.0]

New EGR
new idle air valve
Cleaned out the throttle body and upper intake
New mass air
New tps
New cats
New coolant temperature sensor , but still shows a code for it . I tried 3 of them

When I start the car the RPM jumps to 2000 and slowly goes down to about 1200 .

Any input guys