wher is my temperature control sensor located on 2001 Ford F-150

I got the part to replace the one that set off the check engine lt. but I don't know where it is. HELP PLEASE !!!!!

2 answers
Which temp sensor did you buy? Is it the coolant temp sensor or the cylinder head temp sensor? The coolant temperature sensor is near the thermostat housing and the cylinder head temp sensor is at the rear of the left cylinder head.
http://www.autozone.com/shopping/repairGuide.htm
Autozone has free repair guides here. Select your vehicle and go to "Engine Performance & Emission Controls" for many sensor locations. Good luck!
I am hoping you can my question : I have a F150, 2001 Ford and every once in awhile it will not start, and later it will start. What can this be?