[kmaforty]

Just picked up my N52 330i after dealing with P0344, P0012, P1554 codes, engine stumble and then died. I installed new cam solenoids, which had been cleaned and re-installed with success for last year, and replaced the battery which was low CCA. The cam position sensor (intake) ended up being the culprit. It was running smooth and cleaned up what sounded like clatter for the cams.

I only had about 20 miles on it and experienced engine stumble again, but no engine light. I went back to the shop and found the above O2 codes stored (2c7e - O2 sensor after cat, 2c2b - O2 sensor pre-cat bank1 , 2c2c - O2 sensor pre-cat bank2) and the misfire 29D0. I also went back to my history and looked at the codes prior to the cam position sensor and realized there was a P114B post cat fuel trim O2 sensor too lean bank 1.

Not sure if just replacing the O2 sensors is the fix - if there is something upstream causing the lean A/F P114B. The coils and plugs are all new as of last year. I replaced the pre-cat O2 sensor a few years back, but can't recall the code that was tripped. I also did the valve cover gasket last year - maybe I fouled something in the process?

I don't want to dump a lot of money into this as I just had the repairs above, plus the brake booster and master cylinder replaced and still need to address a leaking oil pan gasket.

Any thoughts on what would be causing the O2 codes and the misfire?

[TDF9]

I'm getting the same thing on my N52: a 2C7E and 2C2B, both bank one.

INPA and google translate tell me:
2C7E - "Exhaust gas after catalytic converter too lean" and "P114B Mixture fine control via lambda probe (bank 1, after catalytic converter) - system too lean"

2C2B is "Lambda probe in front of the catalytic converter, system check", "P2196 - Oxygen sensor (bank 1, before catalyst) - signal stuck on rich", "mixture too rich"

What would cause the a too lean code after the Cat, and a too rich code before it??

[chilledn52]

Just had this code (2C2B and 2C3D) 3 days ago with a o2 sensor I got under 2 months ago. Warrenty'd it again since I bought under a year ago. My Lamda was off target

[TDF9]

Thanks for the reply. I decided to replace the up a upstream o2 sensor and see it that does it. Got it in this morning, so we'll see...