is the color of the sockets the best way to tell, all gray is OBD1 and gray/green is OBD0? what's the best way to tell? thanks.

 

You can tell an obd0 from obd1 ecu when you look at the plugs.. The obd1's are all the same except for the pin count.. The obd0 has one plug(plug A) that is larger than the rest and the pins are spaced further out on them..

 

thanks.