ok this is it, im going crazy over here. i put a simple single vtec swap in my civic cx hatch, i used the ex engine wire harness and now i get the secondary o2 sensor code. i tried to wire a secondary o2 sensor to the ecu but that didnt work. dont know if i did it right. has anyone had this problem.

 

what year civic is it and what year harness is it?

 

http://www.o2simulator.com
30 bucks with shipping, worked like a charm for my 97 dx with ex swap. the SO2 only checks to see if the cat is ok.