First an most obviously, a B16A in a CRX should not have a second O2 sensor. If it does, you're running OBD-2, which makes no sense. I don't know why you would have one, and if it throws no codes I would leave it out.

The knock sensor may be damaged. Code 6 is the coolant temp sensor, is it plugged in?

What ECU are you using? A PR3, a PW0 or something else?