ok here is my setup. 2000 civic si with 92-95 jdm b16 sir-2. Using the OBD1 ecu that came with the motor, but the wire harness from my si. Had to change over the dist., alt., and injectors. My question is, does the second o2 sensor that plugs into the cat make a difference or not? i mean would it matter at all if i removed it? My mechanic says it will throw a code and not run right if i remove it, but from things ive read on here and other boards, this sensor does not matter on this motor. Can anyone help me here?

 

Nope you're fine... It's all based off of what ECU you're running, since you have an OBDI ECU (which only looks for 1 oxygen sensor, i.e. the primary) it doesn't really matter because it can't even see the secondary oxygen sensor anyways...