My 1992 Buick Century Is Accelerated

My car has been accelerated for quite a while now, i went to autozone and they told me to change the air control valve on the body throttle, so i did...then i decided to change the air control sensor on the body throttle as well..after that i took some advice to clean the body throttle inside out..the service engine light was on for quite a while, so i decided to go get it checked out, because i thought maybe that would tell me the problem..the computer diagnostic told me to change the premium oxygen sensor which i did..still accelerated 1. air control valve---on body throttle2. air control sensor ----on body throttle 3. premium oxygen sensor 4. cleaned the body throttle thats what i have done up till now..need help dont know what to do next? i was thinking of changing the body throttle sensor, which other people call the idle speed sensor on the body throttle..but dont want to make that move because its pretty expensive n i need some advice or a least a route to take..