The sensors both of them are located under the intake manifold. Make sure you also replace the short sub wire harnesses to them as that is as much a problem as the sensor itself for setting fault codes.
Nissan technical documentation does not provide a fuse map. In fact not all fuses are needed and you are supposed to chase blown fuses when a problem occurs rather than fill all the empty slots in the fuse boxes with fuses. The roles of individual fuses are explained in the relative sections of the service manual. For example: the fuses relative to light system are illustrated in chapter LT of service manual. Relays and ground system fuses are in section PG of service manual...and so on. You get a complete index of service manual in section IDX.
The complete service and repair manual has been uploaded here. The manual says Pathfinder because Navara is sold as Pathfinder in US and other countries. Click on the green button to get free download. The manual is in compressed format and includes about 30 PDF chapters. Refer to document IDX for index. Refer to individual sections to troubleshoot a problem and locate relative fuses and relay. You find relay maps in PG chapter, I think at page 85, but there is no fuse map provided by manufacturer in Nissan technical documentation.
Here also a short document written by the user that allow to find the different fuse boxes. The information is also present in service manual, but the document explains it in a simpler way: Nissan "Hidden" Fuses.
