iPhoneHome1

Currently driving a 2008 528i with roughly 160k miles.

My engine light came on yesterday while driving down the highway out of nowhere. Car does leak some oil, but nothing out of the ordinary IMO. Idle is normal but I am replacing plugs and ignition coil packs this weekend due to age.

OBD2 scan is giving me error code P2096. Is anyone familiar with this code?

I am leaning towards O2 sensor first but would like some input from anyone else that may have had a similar problem.

Thanks in advance!

Andrew06

I would start by buying a BMW specific scanner. I have the creator c310, and though it looks like a knock-off, it is very capable of BMW-proprietary tasks. Plugs and coils are a good idea just because of age, beyond that i would clear the code and see if it comes back, you may get lucky.

iPhoneHome1

I purchased the c310 scanner however the engine light went away before it arrived. I changed the coil packs and plugs and the car has run great the last 5k miles... but the engine light came back yesterday and is throwing error: "2C31 - Oxygen sensor before catalytic converter, trim control error". I can clear it but it comes back soon after.

Can anyone help point me to which sensor this is and a specific part number? I'm having trouble finding anything on google. Thanks for the help everyone!

iPhoneHome1

Can anyone help me figure which sensor I am looking for? This thing is driving me nuts going On and off every couple days.

seanjordan20

2C31 - Lambda probe in front of catalytic converter, trimming control Typically caused by the wrong O2 sensors in the wrong downpipe or a major exhaust leak. Grey wire loom goes to the back pipe, black wire loom goes to the front pipe.

iPhoneHome1

Lambda Probe Bank 1 (cyl 1-3) Part number 11-78-7-558-055 for anyone looking in the future - $298.58 from the dealership. 1.5 hours to replace. Engine light is out. Thanks for the help.

iPhoneHome1

500 miles later the engine light is back on. Same code "2C31 - Lambda probe in front of catalytic converter, trimming control".

Exhaust Leak?
Crank Case Ventilation Valve (oil separator?)?
MAF sensor (I already cleaned it with cleaner - no dice)?
DISA Valve (does the e60 N52 even have one?)?

I don't know where to begin. Suggestions please.

iPhoneHome1

Replaced the bank 1 sensor 2 post cat sensor (green arrow) and manually reset the check engine light. 1k miles so far and it hasn't come back on yet.