These are very common failures on our aging Second Gen Xterras and I wanted to get the information out there for those who are in need of it. First and foremost: If you've changed one of these with an auto parts store or Amazon part and are still having issues or getting the same code, it's because no one has any luck with the cheap knockoff parts. Buy Nissan or Hitachi (OE part provider). Courtesy Nissan or Rock Auto have the best prices on them but your local dealer might match Courtesy and I've heard that AutoZone can get the Hitachi but have never tried to verify that. Signs of failure are VDC, ABS and CEL all illuminated and need to be verified with a code reader (I'm not responsible for you dumping a bunch of money into sensors because you won't buy a code reader). Generally the vehicle will run but suffers from loss of power, although a dead Crankshaft Position Sensor will cause a no-start condition. Camshaft Position Sensors: The cam sensors are on the rear of each cylinder head. I was able to change mine going over the top of the engine and using a 10mm wrench. I'll try to get some pictures to add when I have the hood up again. Being foreign designed, Bank 1 is the right or Passenger side in North America. Bank 2 is left or Driver side. Part Numbers: Bank 1: Nissan: 23731-9J90D Hitachi: CPS0008 Bank 2: Nissan: 23731-AL61D Hitachi: CPS0005 As far as I've found, everything from 05-15 with the VQ40DE uses the same sensors but there have been updates to them so the sensor you take out might not be EXACTLY identical to the one you replace it with. Crankshaft Position Sensor: This is a little trickier to get at and it is necessary to remove the right front inner fender liner to access it. If you haven't done this before, it takes a hand full of Phillips head screws and 1-3 push style fasteners depending on how many times it's been done before. Learn to do this because just about anything you do will require it in the future. The Crank Sensor is located on the side of the block, just behind the cylinder head above the catalytic converter flange. The connector is covered with a rubber boot. It's been a while since I did mine but I believe I used a deep well 10mm socket and stubby ratchet to remove the bolt. Others find a swivel socket on a short extension to be handy for this. You'll notice when you remove the sensor that there's no o-ring on it. This sensor is in the bell housing and doesn't need sealing but some people have ordered the o-ring and used it. Either way is fine. I did not use an o-ring when I did mine. Part Numbers: Nissan: 23731-EA20D Hitachi: CPS0017 Nissan (and Hitachi I believe) have updated the Crank Position Sensor since most of our vehicles were manufactured. The new part comes with a metal sleeve over the lower portion and the connector is clocked 180° from the original. Gently twist your harness plug and it will work just fine. I like to use a light coating of dielectric grease on my connectors and o-rings when I install new sensors to seal moisture out of the connectors and help with installation. I'll try to add pictures as soon as I get some. If anyone has pictures I can use, pm me and I'll add them to the thread in the proper place.