To find it, you'll need to:
1. Consult a repair manual: A repair manual specific to your year and engine will provide diagrams and precise locations. This is the most reliable method.
2. Look under the vehicle: Get under your Tacoma, ensuring it's safely supported on jack stands. The exhaust pipe runs from the engine, through the catalytic converter (a larger metal canister), and then continues to the muffler. The rear O2 sensor will be threaded into the exhaust pipe *after* the catalytic converter.
3. Follow the wiring: The O2 sensor will have a wire harness leading to it. Tracing this harness back can help you locate the sensor.
Important Safety Note: Working under a vehicle can be dangerous. Always use jack stands and never rely solely on a jack. Also, the exhaust system will be hot even after the engine has cooled down for a significant time. Be careful not to burn yourself.
