P0139. 2005 civic 1.7l SE Manual with air.

Question

P0139 Honda - I have replaced this O2 sensor, cleared the code, pulled the ECM fuse and still the light comes back on tell me the same sensor has the same problem. I clear it immediately after reading the code and the car is fine again for about 4-500 kms. Light comes on and i clear it, runs like a charm till the light comes back on again. When engine light comes on, it doesen't lose much power, but it is noticeable with a little bit of a misfire or something (car kinda lopes in idle and hunts around a bit).
Any idea what could be doing this? Upper and lower 02 sensors are new.
Thanks in advance!
Blair.

Answer 1

P0139 - 02 sensor slow response Bank 1 Sensor 2

This code is for the downstream 02 sensor. When the engine lopes and hunts in idle this is when the code comes on. . Honda has a TSB for this condition , TSB# 07-019.What this is for is the ECM misinterprets the secondary heated 02 sensor and set P0139. the fix update the ECM software.