how do i fix a p0118 code

I'm guessing from your answer that you (like so many) think that replacing a sensor fixes something. That only fixes a defective sensor and that's assuming the sensor was defective in the first! If you cleared the code after putting in a new sensor then the new sensor is defective OR MAYBE -JUST MAYBE there is SOMETHING WRONG that the first sensor was trying to tell you about! I don't know which temp sensor it is (and that's immaterial to what you need to do). Find out what temp that sensor was designed to monitor and then see what is making that system screw up.