hi guys, i am new with this. I am replacing my old engine harness but i got confused where is connected this plug

 

Looks like dash harness to underdash fuse box

 

It s been reaaly hard to unplug the connector to find out if its matchs. the plug is on a support which i dont kno w how to take off without brake in a bunch of pieces, do u know a way to remove the plug avoiding messing up?

 

I also bought this harness and have no idea where that plugs into, having trouble getting the car started also

 

I have your answer sir, it is the dash harness , for obd2 it will be the green connector on your factor ecu
the harness you have is a obd2 to obd1 harness, the long remaining grey connector needs to be adapted to your obd2 chassis harness using this adaptor

 

Oh this is very informative. but now i am confused. According to the product and seller this is a Odb1 harness, this is plug should i left unused or i have to connect it in c101 plug under the dash ? I am guessing this will send information from the ecu to gauges or is useless in my case? my car is a Civic ex 93 obd1