Are the n/a 90-91 ECU's interchangable with the 92-94 n/a's if they are both 4eat's?

From what i have heard and seen, Yes you can USE them and it will WORK...but it wont take advantage of any ugraded injectors or anything if there is any......hope this helps

The 90-91 ECU's are different from the 92-94's.

 

There are some injector differences between the 90-91's and the 92-94's which can cause some ill affects. I experienced this first hand when I swapped 92-94's injectors in my 90 legacy.

 

I've since put in a 92 ECU. One thing that was different was the MT/AT identifier pin.

 

I'd personally try and find an ECU for your specific model year grouping.