What's this? Knock Sensor?

[Interjon]

I found this in the bottom of the bilge after a session yesterday. Boat ran fine. I believe it is a knock sensor cap. Can someone confirm, and let me know where it goes? Is it something I should even concern myself with (and just ziptie somewhere). If it is a knock sensor, you think it would have sent a warning if not attached (or maybe that is not how they work). Any information would be hugely helpful.

Boat is a 2003 196 with 5.0 sport engine.

Thanks in advance.

[jpwhit]

It does look like a knock sensor connector. There is typically a knock sensor on each side of the block screwed into the block drain hole. They don't alway generate a check engine code, but if they aren't connected or working properly, the ECM will often retard the engine timing to a very safe default. Which means you'll lose some power.