hx-b16hybrid

okay so this is kind of a repost but not really. my car is a 97 civic hx coupe. i swapped in a 00 si b16. i have the engine wiring harness for the 00 si which plugs into everything on the engine and one of the two o2 sensors and goes through the firewall to the ecu. the ecu takes 3 plugs but the harness only has 2. i have a p2t ecu and want to run that. my question is which harness is it that plugs into the other o2 sensor and last spot on the ecu ? my best guess is the cabin harness. now i've had the suggestion of using a 96-98 ex wiring harness which then would let me use a couple of ecu's and i understand that would work and i appreciate the help with that, but i REALLY want to know the answer to my question as opposed to just a work around. i would really rather use the p2t ecu and have everything done correctly. so is the 00 si cabin harness the one i'm looking for ? and if so will that work correctly for me if i just swap it out with mine ? will it be plug and play with all the original connections throughout my car ? thanks a lot to anyone who can help me with this.

hx-b16hybrid

*bump*