What is the meaning of OBD-II code P0137, and what are the possible causes and solutions for this code to be generated?

The P0137 is an OBD-II code indicating that the bank 1 sensor 2 O2 sensor is not increasing its voltage output above .21 volts, signaling excessive oxygen in the exhaust. This occurs when the ECM sees a low voltage from the sensor despite commanding a rich fuel condition on that engine bank. There are several possible causes for a P0137 code, such as: --The ECM detects low voltage issues and activates the Check Engine Light. The ECM uses O2 sensors to regulate fuel injection. -Exhaust leaks can also cause issues. To diagnose the problem, a mechanic typically scans codes and freeze frame data, monitors O2 sensor data, checks wiring, and connections, inspects the sensor for damage and contamination, checks for exhaust leaks, and follows manufacturer's tests. The P0137 code can be resolved by replacing the O2 sensor, fixing the wiring/connection to the O2 sensor, or repairing exhaust leaks prior to the sensor. It's important to note that the O2 sensor for bank 1 sensor 2 helps the ECM control the fuel-to-air ratio by giving voltage feedback on oxygen levels in the exhaust, and low voltage can indicate excessive oxygen or issues.