it is recomended when doing knock sensors to replace both sensors and harness with oem.
beware of where you purchase the sensors because there are knockoff's all over the internet
best to purchase from a dealer or well known retailer/auto parts store.
when installing the new sensors apply silicone around the top cover to help prevent water saturation causing rust.
I personally also recomend using fel-pro metalized intake gaskets when doing the sensors.
it's a fairly easy straight forward job if done properly
this video covers it, the difference will be a drive by cable instead of drive by wire
the video is available on youtube just click the play button