crankshaft position sensor Help ???

I own a 1999 Honda Hatchback CX.It has the D16Y7 engine.I was driving and this yellow engine check light came on.I pulled the engine codes out of it and they are P1337 with the scan tool and with the paper clip it is CKF- crank fluctuation sensor.Where is this located and how to clear the code besides using a scantool.

the sensor should be on the back lower side of the block. if you want to clear the code try unhooking the battery for about a minute or two.