1991 oldsmobile cutlass problems starting

i have a 1991 cutlass ciera with a 3.3L, one day it lagged power and would not go over 10mph without stalling out. i checked the computer and it gave me a high voltage TPS reading, which i replaced along with a few other parts and still no luck. i have fuel pressure and spark, but i am stumped and need more insight on what to check before i spend more money on new parts.