if you wanna change ur ECU to older one, get a used one. a fair price for a used will be around 100$
u also need to change ur knock sensor in order for it to work, thatll cost you 150$ brand new.
labor will cost you about an hour if they do the shortcut way or else will take a while.
i really recommend you do the easy way, cz the long way to change the knock sensor you have eto mess up some gaskettes, and you dont wanna do that on a brand new car. theres instruction on the other site