OBDI vs OBDII

My buddy got a 1997 GSR not too long ago. He wants to start modding it but wants too know if the gains will be worth it, or, should he get a pre-97 OBDI ECU?

First of all, the OBD II was implemented for the 1996 model year, so if has wants an OBD I he would need to get it from a 94 or 95 Integra. Just wanted to clear that up...

Now, there really is no reason for him to run out and get an OBD I ECU just yet. Chipping or replacing your ECU is one of the LAST mods done to your car. You really only need the modified ECU when you have fully built your engine, so that it may be used to its full potential.