To be absolutely certain, you should:
* Consult your vehicle's repair manual: This is the most reliable source for the precise location.
* Use an online parts diagram: Many auto parts websites (like AutoZone, Advance Auto Parts, etc.) allow you to select your vehicle's year, make, and model and view diagrams showing the location of various parts. Search for a diagram that shows the engine components.
Do not attempt to locate or work on the sensor without proper tools and safety precautions. If you are not comfortable performing this task yourself, take your vehicle to a qualified mechanic.