ok...settleing this once and for all....me and my friends just aren't sure what obd this thing is....
everyone on HT says its obd-0...which fine i guess..but its plugging into my obd2a to obd1 harness conversion...secondly..it has no blinkie light...

next...they made an obd2 pr4 too...but it wont work...tried that its clealry not made for that....

so..final question is...they made the pr4 for 92-93 ls's.. did they change the harness to obd1 looks with keeping obd-0 programming...?? if so thats sucks...cause CEL 10 isn't liking me right now...and its my only one...

 

There is a 92-93 PR4 ecu. It's obd-1. It should be easy to tell the difference between the 90-91 OBD-0 PR4 and the newer 92-93 OBD-1 PR4. The 92-93 ecu doesn't have the code light on the ecu and the wiring is different than the 90-91.