I am building a ls-vtec for my 90 si and I was wondering can I just use a obd 0 ecu and convert it to vtec and tuned it or is better of going with a obd 1 vtec ecu and use the jumper harness?

What if the benefit of having obd 1 over obd 0 and vice versa I know that obd 1 has more sofware to tune it with but, other than that what is the benefit of running obd 1?

 

It depends on how far you go with you're engine power wise. You'd want to up grade to obd1. You can edit some of the obd o roms in crome but you can't edit all the things you can in bre or turbo edit. The 89-91 models are 28 pin. PM6, PM7, PR4,