don't worry about it, its a non check engine light item.

Ever heard of a "repair manual"?  Go buy one.  Most auto shops carry
one for specific make and model cars.  You can also get one from a
Nissan car dealer.  Which is more expensive but usu. better.

Yes, you have to remove parts to get to it.  For some Nissan vehicles
dealers have what they call a knock sensor replacement kit, which
includes the knock sensor and the other seals/gaskets that you need to
replace when removing parts to gain access to the KS.

Good luck

AS