I searched the forums and couldn't find any hits with this code so I thought I'd make a new one and ask for advice. The check engine light came on yesterday morning but I wasn't having any problems with the car. I took it in this morning and when they ran the diagnostics it came up with the P0137 code. Since I was under warranty they replaced it quick and I was out the door in an hour. After some time on google it looks like it's an O2 Sensor? Does this mean my catalytic converter might go next? Jackie
This code's description is 'Oxygen Sensor Circuit Low Voltage (Bank 1 Sensor 2)'. This is the post-converter sensor, which confirms that the catalyst did its job. A low voltage indicates that the O2 sensor is reporting that there is a lot of oxygen in the exhaust. The computer thinks the voltage being reported is so low as to be a bad reading - that in fact it represents an open circuit (not connected). Generally this code means that the sensor itself has failed, electrically. It doesn't have anything to do with the actual functioning of the catalytic converter. If the code is repeatedly posted with a new sensor, it could indicate a hole in the catalyst letting in fresh air. Generally, though, the car would log P0420 (Catalyst System Efficiency Below Threshold) rather than this code.
Sorry for an old bump but this was the most relevant post I could find. I'm having the same issue and have replaced the o2 and cleared the codes, yet the code still persists. I've ordered a replacement wideband sensor hoping that may solve it, but if it does not; aside from being a bad catalytic converter could it be caused by a leak in the exhaust (as the code is the result of too much oxygen in the exhaust)?