In the U.S., ODB-I was mandated beginning in model year 1988, and ODB-II was mandated for all cars beginning in model year 1996. Technically, California mandated it, but the manufacturers all made their entire U.S. models comply with California rules for easier logistics.
ODB-I had terrible standardization and requires a bunch of model/make specific stuff to properly interface with, but in theory the 35-year old cars do have some kind of data port available.
In the U.S., ODB-I was mandated beginning in model year 1988, and ODB-II was mandated for all cars beginning in model year 1996. Technically, California mandated it, but the manufacturers all made their entire U.S. models comply with California rules for easier logistics.
ODB-I had terrible standardization and requires a bunch of model/make specific stuff to properly interface with, but in theory the 35-year old cars do have some kind of data port available.