Just a quick question;
Do you replace everything you get a code for?
Knock sensor was because the thing was that hot it was vaporising the fuel that well and advancing combustion that much, that it knocked it's guts out until you stopped it. I would say that the oxy sensor is possibly purge solenoid related.
Fault codes are to advise that a sensor is 'out of range' or 'has an open cicuit', in your case, the ECU knocked 5 degrees of ign out of the map, and the thing kept knocking as described above. The ECU simply deduces that the Knock sensor is 'out of range' or faulty, and throws the CEL on.!!
(man YOU CAN TYPE!!)
Cheers
Sixpack