I am changing my 92 golf obd1 to obd2 I have a doner 96 obd2 golf. I have the machanical side. I have taken off the engine harness from the obd2 car but the how much of the actual wiring loom do I need? Do I need to replace the whole loom? Also on the obd2 car it has gear sensors and the obd1 car doesn't will this need to be changed over?