1st check to make sure the connection to the fuel temp sensor (located on the fuel rail between the #2 and #4 cylinders) is good and clean. If the sensor connection is good, then replace the sensor. Just unscrew it and put in the new sensor. No need to release the fuel pressure or anything like that. The sensor doesn't really touch the fuel.

 

In addition, verify the ground strap is in place on the rear of the drivers side fuel rail. If the ground is not in place, it will throw the fuel temp sensor code.

Tim