I have a 2002 LX Honda Civic. And the Stupid Converter is installed with the header in front of the engine. I bought a new header, and it doesn't have the Catalytic converter. What I want to do is make an LX look like an EX, have the converter in the middle of the car. I just want to know if it is possible, because it has two 02 sensors, which I would have to make longer, which I'm not sure if its a good idea, and I don't want to make it a dummy O2 Sensor, unless I have too.

And another thing what would happen to the second O2 Sensor if I were to get a Cat-back exhaust?

 

If you get an EX header, EX converter, and EX cat-back, everything should bolt straight up. You can buy extenders for your 02 sensors (I believe Password:JDM carries them) or you can lengthen the wires yourself (if you don't have experience soldering I wouldn't recommend it).