Originally Posted by JoePannone
what year is your civic? if its OBD1(92-95) then there is only one O2 sensor that should be screwed into the bung on the header and thats it. if you have an OBD2(96 and up) car then there would be one sensor in the header and one after the cat. you wont pass emissions without your O2 sensor/s and you probebly have a CEL on.
Its a 98. and your right its an OBD11. I have both of the o2 sensors still. Right after i had it done (full exhaust) they put both of the o2 sensors in front of the cat. I took it back because my cel was on and the o2 codes were coming up. Realizing they had put both the sensors in front of the cat i had them fix it, or so i thought. now there is one right before the cat and one right after and they cut the wires to extend them. Do you think it could be the wires are too close? or that the wires were cut to be extended? I have exhausted myself with possibilities. Is it because there is no o2 sensor in the header, instead its right in front of the cat?