I started getting a 0141 code (bank 1 sensor 2 O2 sensor heater circuit).

Only happened when ambient was cold. Reset CEL and it would stay off for a day or two.

Replaced the 1-2 sensor but before replacing I measured the Ω on the heater and it read normal so I also measured the voltage on the heater when starting and it started about 9.5v and climbed to 12. The 2-2 sensor behaved the same way.

Since I already had the momentum I changed the 1-2 sensor and no error for a day or two but then it came back and now it trips every cold start.

I thought I read that interaction with 1-1 sensor or SAP can cause the error.

I haven't either measured actual current draw (have to cut the wire to do so) or swapped the banks to see if the error would move (to determine if I bought a bum part).

I get voltage on the heater circuit, I get normal looking values from all four sensors though 2-2 reads consistently lower so I'm thinking of replacing that one to make them more similar.

Confirming does anybody know for certain that bank 1 sensor 2 is the outboard (starboard) side? Maybe I changed the wrong one.

I don't want to shoot a parts cannon at what should be a simple fix. I don't know where the other end of the wire comes from there might be a short from a previous oil leak does anybody have experience with this situation?

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)