Sure this has been answerd before but i have a 89 si intake will it matter to run a 91 si ecu from a crx/civic si or will i want to use the 89 ? any diff if i get a 91 harness will work with the 89 intake? thanks

 

doesnt matter if you use a 89 si ecu or 91 si ecu,,the 91 will be better if you have plans for chipping the future though.