98 civic "HX".. swapped a 97 "EX" harness, engine, and computer into my "HX" to sell it off. But I'm stuck and throwing a code for secondary 02 sensor low voltage. The "EX" has a sensor or something for the emission system by the fuel tank assuming that the oxygen sensor ties into. On the original EX car the secondary 02 sensor plugged into a spot just under the dash board that runs up by the guage panel. The HX doesn't have this plug.. so I tried to wire it directly to the computer and 3 out of the 4 wires are good. But the black wire that is supposed to go back to the tank is messing this up. Can you guys help me out? Thanks!