it is located in within the throttle body assembly. When you clean the flame trap you would see the TPS sensor - black square like thing screwed (2)to the TB. fairly easy to clean or replace. The usual problem is that the TPS contacts are just dirty w/c eventually sets of codes. Try cleaning the contacts w/good contact cleaners or even di-electric grease/contact cleaner or plain WD40 and make sure it is air dry before reconnecting terminals.
good luck
94 850 wagon n/a 195k
90 760 turbo wagon 160k