4doorcivic

ok look i got a integra its a 1990 it was t boned so i has a b20 in it its ben converted to obdo and i put it in my civic ef 91 and some wire harneses fit together and then there is a harnes on my car it has a yellowish cover on it and its rektangular wtf dose this do and can some one fine me a step by step wireing or a diagram im ****ing cunfussed im willing to pay for some one to do it i still have the integra so yea