New Genuine Nissan Camshaft Position Sensor or Cam Angle Sensor (CAS). Make sure you adequately diagnose your sensor before replacing. Often symptoms of a bad units could include failure to start, hard starts or sputtering, no power at highway speeds and poor engine performance.  This unit is made to inform your Nissan computer about the position of the cam to the crankshaft relation and adjust spark timing and fuel injector operation to offer optimum power and fuel economy.