Yes, the knock sensor is literally a very sensitive microphone that listens for knocking. When you replace it the bolt must be torqued exactly for it to work properly.

You can test the knock sensor by tapping on the engine block with a metal hammer. That sounds just like a knock to the sensor and should upset the idle a bit.

-J

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
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2013 Fiat 500E.