P0137 O2 Sensor Fault on 2002 Chevy Tahoe: Diagnosis and Fix

What brand of oxygen sensors did you install? Did you confirm that the sensors were installed on the correct engine bank? On some GM trucks, a plugged catalytic converter in one bank can trigger O2 sensor-related codes like P0137.

For reference, here's an official guide on P0137 code interpretation: http://www.obd-codes.com/p0137

jeff compton wrote: What brand of oxygen sensors did you use? Are you sure you changed the ones on the correct side of the engine? Maybe the converter is plugged on that bank and can sometimes generate O2 codes on GM trucks. I purchased two new Bosch oxygen sensors. The two I replaced were on the right side of the engine, which has a single exhaust pipe with one catalytic converter. I swapped out the sensor before and after the converter. Could I still need a new catalytic converter?

I recommend removing the Bosch sensors and replacing them with OEM or factory-approved sensors from your dealer's parts department. Also, inspect the wiring harnesses to the oxygen sensors and verify there are no exhaust restrictions or leaks.

lowridinhotrod06 wrote: I replaced two O2 sensors on my 2002 Chevy Tahoe when the service engine light came on. I swapped out the one before and after the catalytic converter, reset the code, but it returned. What do I do now? After checking under the truck, I discovered there were actually two additional oxygen sensors on the driver's side—thank you, Jeff! When I visited my mechanic six months ago, they replaced sensor 2 on bank 1. Today, upon inspection, I found that the sensor was installed backwards. I bought two new sensors and replaced them on the driver’s side. I also tapped the catalytic converter to check for looseness—it sounded fine. After resetting the check engine light today, I’ll monitor the system over the next few days to see if the P0137 code clears. Thanks, Jeff!