See this link FIG : 350Z engine compartment component locations
There are 2 camshaft position sensor locations, bank 1 and bank 2.. ( Bank i is the side with cylinders 1,3, 5 and bank 2 is the side with cylinders 2, 4, 6 ).
Check the vehicle for fault codes to see if there are any sensors were involved to the malfunction of the engine.
Local auto parts stores such as Autozone ( not in California) or Advance Auto parts will scan and retrieve any diagnostic trouble codes ( dtc ) stored in the powertrain control module for free of charge..
2. Amazon.com has the code reader for less than $21.00 dollars.
3.Re-post the dtc's in here " answer question " for further assistance.
Note: we need the dtc's to identify the sensor, there are a dozen different sensors to operate the car.
Visit this site and see all the different sensors.
Navigate to this site and see the code reader