* Upstream (before the catalytic converter): Usually in the exhaust manifold or very close to it. This is the most common location for a front oxygen sensor.
* Downstream (after the catalytic converter): Somewhere in the exhaust pipe after the catalytic converter.
To find them precisely:
1. Consult your vehicle's repair manual: This is the most reliable method. The manual will have diagrams showing the exact location of the sensors for your specific engine (4.3L V6, 2.2L I4, etc.).
2. Use a repair manual app or online resources: Websites like ChiltonLibrary.com or others that provide repair manuals often have diagrams. You'll need to specify your exact engine size.
3. Look under the vehicle: With the engine cool, get under your truck and visually inspect the exhaust manifold and exhaust piping. Oxygen sensors are typically threaded into the exhaust system and have a wire harness connected to them. They usually have a metal housing and a ceramic tip. Be cautious; exhaust components get very hot.
Important Note: There might be more than one oxygen sensor depending on the emissions system of your specific S-10. If you're unsure, it's best to consult a repair manual or professional mechanic.
