I scanned my 99 accord and i received the P0138 and P0137 codes. They both refer to the O2 sensor at the same area but how conflicting definitions. It says the sensor (bank 1, sensor 2) has both a high and a low voltage... Is that even possible? When I erased the codes it did not reappear. Does that mean the problem was just a minor malfunction?

 

Dirty connection of O2 sensor to harness can cause this problem. Signal voltage is small and any resistance at connection will cause problems. If it appears again, remove connector, clean w/ contact cleaner, and reinstall.

good luck