What are the visual differences between lets say a gsr obd1 and obd2 dizzzy? are the plug ends the same, im not sure myself, but i would like to know, also what differences in engine harness wiring is there, i know about the o2's , but stupid **** that i never really thought about looking at.
Tahkns in advance.

 

simple...obd2 have two sensor, obd1 have one. engine harness will also be different becuase of dizzy. is this what you are asking.

 

https://honda-tech.com/zerothread?id=577638