I recently purchased an old 90 cavalier, and I believe I may need to replace the ECU. I know there are many other things that could have gone wrong, but I am pretty sure it is the computer. My question is, if I was to purchase a new ECU for it, does the 1990 need to be programmed? I know that all newer cars need to be, but a friend of mine who works for GM said that it does not need to be programmed in older cars. Any advice? The car sputters and has problems accelerating. Is also burning rich.

-Cavalier
-1990
-I believe it is 2WD
-2.2 liter engine
-coupe