not sure on that.
but if not mistaken ek9 2000 using obd2b n the ecu cannot fit to the obd2a socket like ek4 one.
the ecu size oso smaller than normal b-series ecu size.
This DIY is applicable to ALL Japanese cars as they share the same Air Con system. This is a long posting as I am covering cleaning for Washable and Not Washable Air Con Filters.