Knock Sensor code? Causes Replace?

Thanks guys, you are too kind

I figured instead of getting new sensors that are at least $70 a piece and will fail the same exact way, just rebuild my original ones. The insulation I used is silicon coated fiberglass rated up to 200C so should be plenty. It seems it doesn't actually take long for the original BOSCH insulation to fail. I replaced my intake camshaft position sensor a year ago and now noticed that the cable became very stiff already...

There's a quest for a method of testing the BMW E39 knock sensors over here today:
- > E39 (1997 - 2003) > knock sensor ohms

Cross referencing to this knock sensor thread today:
-> E39 (1997 - 2003) > missing knock sensor

For reference, here's a thread that shows pictures of the knock sensor in situ:
> E39 (1997 - 2003) > kNOCK SENSOR 1



EDIT: Since this thread is the canonical one in the bestlinks, here's a set of related E39 knock sensor threads:

• Misfiring under load - KNOCK SENSOR!
• Knock Sensor code? Causes Replace?
• Knock Sensor 1 & 2 Mean Value
• Knock Sensor #4
• 540i Camshaft Vanos Control / Knock Sensor Fault
• Knock Sensor Woes
• knock sensor on 540i -- how robust?
• Knock sensor - angle important?98 540i P1384 Knock Sensor 3 Circuit
• kNOCK SENSOR 1
• Help!!!!! Knock sensor and fuel trim codes
• Installed new Knock Sensor, nice coolant leak now!

etc.