Each HHO guide we have on our main site has workable EFIE schematic in it to build your own. I'd just buy one if I were you. They are cheap and reliable. You can find EFIE devices here (click link)
For detaching the O2 sensor, do you mean using O2 extenders? Extenders are small tubes that you put in where the O2 sensor is now. Then you screw your O2 sensor into the extender. This will move the O2 sensor away from the flow of exaust and effectivly make the O2 sensor read less oxygen. It works well. You can also install a EFIE as well.
Does this help?
EddieRock




