What is the meaning of OBD-II code P0131, and what are the possible causes and solutions for this code to be generated?

P0131 indicates a problem with the left side (bank 1) oxygen sensor 1 (before the catalytic converter) and could mean an issue with the air-fuel ratio or improper voltage from the sensor. There are several possible causes for a P0131 code, such as: -Faulty Oxygen Sensor/Air Fuel Ratio Sensor. -Incorrect operation of the Oxygen Sensor/Air Fuel Ratio Sensor Heater circuit. -Leakage in the exhaust system. -Leaks in the intake air system, including vacuum leaks. -Low fuel pressure. -Malfunctioning engine coolant temperature sensor. -Problems with the wiring or circuits connecting to the sensor. -Need to update the PCM software version. -Defective PCM unit itself To diagnose a problem, a mechanic will use an OBD2 scanner to check for codes and freeze frame data. If code P0131 is confirmed, the mechanic will clear the code, take the vehicle on a test drive, and check the oxygen sensor voltage and resistance. If there is a fault, the technician will inspect the wiring, and if it's okay, check the sensor voltage and resistance. The resolution for the P0131 code depends on the cause. Check with a scan tool, clear the code, and road test to confirm P0131. Visual inspect the wiring, check voltage/resistance, and replace the sensor if needed. Oxygen sensors are designed for long-term use but can have issues as the vehicle gets older and hits 100k miles. These issues can affect driving, fuel efficiency, and engine health, so it's important to address the issue promptly.