@gmut, Yes I did. I think I changed both knock sensor. Did the same again last year. I changed only one. you need to be careful with a new ones, if you drop it it can become faulty. If you don't have the diacom software, change them both, it might be cheaper than having a mechanic plug his computer and changing a part that is simply screwed in the block like any regular bolt.
If you have the diacom, it will tell you knock sensor 1 or 2 (if you have the same engine as mine). to know which is whcih you just unplug one and run the boat then unplug the other and run again and you will be able to figure out which is where. very simple fix and yes the boat runs fine even with the light on.