i have a problem i caint find the other connection that goes on the ecu the one that should split from the green connector on my car so right now only 2 connectors are on the ecu i dont know what to do can somone please help let me know
its an obd2 99 si my hb is a cx 96

 

it sounds like you're using 99-00 si harness

you need to use a 96-98 ex harness, or your original harness wired for vtec....

 

i have the cx harness from my d16 but i dont think it would fit the si motor or the si ecu you think i can buy a wire harness

 

ok thats perfect the harness does fit the motor but you'll have to mod it a little don cut any wires just slice in to the loom and pull the plugs to were they supposed to be....

and for the ecu what i did on my was just get a jumper harness to obd1 and ran an obd1 ecu.. you can also get a jumper harness from obd2a(96-98) to obd2b(99-00) this one will let youy run the Si ecu and (or) pass emission if you do it right