How do you know if car needs new CPU? on 2001 Nissan Sentra

car will not go over C25mph. replaced TPS-no results.
Dealer says needs CPU. I just put one in a year ago (used)
Called first owner-she said same thing happened and she
replaced the CPU and sold the car.
This is a manual tranny.

Asked by for the 2001 Nissan Sentra
something else is causing your issues. look for root problem no just fix cause