When servicing an oxygen sensor, exercise special care as it has a permanently attached pigtail and electrical connector that cannot be removed; any damage or removal will ruin the sensor. Keep grease, dirt, and other contaminants away from both the electrical connector and the sensor, and avoid using any cleaning solvents on it. Handle the sensor gently to prevent dropping or rough handling. Since the sensor is installed in the exhaust manifold or 
Catalytic Converter, which contract when cool, it may be difficult to loosen when the engine is cold; therefore, start and run the engine briefly before attempting removal, taking care to avoid burns. The sensors are located near the exhaust manifolds at each primary catalytic converter, with an additional rear sensor in the exhaust pipe beneath the vehicle. If working on the rear sensor, raise the vehicle and support it securely on jackstands, which may also assist in removing a front lower sensor. Remove any components that obstruct access to the sensor, as these can vary by model year and installed options. Disconnect the sensor pigtail and release the wiring from any retainers before unscrewing the sensor, using special oxygen sensor sockets available at most auto parts stores while being cautious not to damage the hex on the sensor. Installation follows the reverse order of removal, ensuring to coat the threads of the oxygen sensor with anti-seize compound and tighten it to the specified torque.