To be certain, you should:
1. Consult your vehicle's repair manual: This is the most reliable source of information. The manual will have diagrams showing the exact location of all sensors.
2. Use a repair database: Sites like Chilton, AllData, or Mitchell offer detailed diagrams and repair information for specific vehicle years and makes. (These often require a subscription.)
3. Visually inspect the engine: With the engine cool, carefully examine the engine block near the oil filter. The sensor is usually a small, cylindrical device with one or two wires connected to it. Be cautious of hot surfaces and moving parts.
Remember to be careful when working around the engine. If you're not comfortable working on your own vehicle, it's best to take it to a qualified mechanic.