I've been consistently getting this error code (if I clear it, it comes back after 15 miles of driving or so).

============1==============
P0141
Raw code: 0141
ECU: Engine control unit
Status: Confirmed
OBDII: Heated oxygen sensor (HO2S) 2, bank 1, heater control - circuit malfunction
Mini: O2 Sensor Heater Circuit
===========================


I've also gotten P0136 (also O2 sensor related) but that one never came back after clearing.


I'm also noticing terrible city gas mileage, about 12-15MPG. Ok I drive aggressive but not that aggressive. Funny thing is, on the highway the gas mileage is completely normal and about 32-34MPG. I've never dealt with an O2 sensor before but I'm guessing this could be causing the system to inject more fuel than it needs, thus causing the bad mileage? And why would it not be an issue on highway driving?

So I guess my questions are:
- Do this error code seem to be causing the bad gas mileage? (and if so, why not on the highway)
- How hard of a job is it to replace this sensor? I don't mind doing it myself unless we're talking you have to remove 10 parts to get to it.


Thanks all

 

Yes, it's likely causing your bad mileage. If the built-in heater isn't working then your sensor isn't getting hot enough to operate properly which will give erroneous signals. For why it's only city driving I'm not entirely sure but could be because the sensor is getting hotter while highway driving due to the engine being under a greater load. Under these conditions it may give a more accurate signal.

It's pretty easy to replace, you'll probably want to make a small investment in an oxygen sensor wrench.

 

@mrbean thanks, that makes sense. I'm going to get a new sensor and wrench - first want to get my hands on a bentley manual

 

This thread was specific to the O2 sensor code, but before opening a separate thread I wanted to ask about OBD vs DTC engine codes – is there anything a BMW specific scanner is going to tell me that I can't get from this website for example? https://my.obdcloud.com/dtc_codes/bmw/dtcs

Below are all my codes (duplicates removed), and only one of them is OBD. The MINI DTC codes however I can get a short description of the problem through that website. I put a link next to each code with the BMW specific error description:

It's a lot of codes, but before I try and diagnose them individually, I wanted to see if they signify anything to anyone here, with more knowledge than me.

- some of them are all related to O2 sensor
- a lot of them are relative to faulty lights. I will double check but all my main light functions are working correctly
- there is one about the triptronic switch. I do notice that when I go into manual mode, the car still downshifts for me. Also the paddles seem to work when I'm not even in manual mode. Its very strange


Car Scanner ELM OBD2
DTC report
Selected brand: Mini
VIN: WMWMM3C55ATP94473

============1==============
P0141
Raw code: 0141
ECU: Engine control unit
Status: Confirmed
OBDII: Heated oxygen sensor (HO2S) 2, bank 1, heater control - circuit malfunction
Mini: O2 Sensor Heater Circuit

============2==============
2A56 (https://my.obdcloud.com/dtc_codes/bmw/view/DME/2A56)
Raw code: 2A56
ECU: Engine control unit
Status: Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault has been present during this drive cycle

============3==============
523B (https://my.obdcloud.com/dtc_codes/bmw/view/EGS/523B)
Raw code: 523B
ECU: Transmission control unit
Status: Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request

============5==============
2A7F (https://my.obdcloud.com/dtc_codes/bmw/view/DME/2A7F)
Raw code: 2A7F
ECU: Engine control unit #1
Status: Test conditions are met, Validated and stored in non volatile memory, Validated fault has been present during this drive cycle

============8==============
5DAE (https://my.obdcloud.com/dtc_codes/bm...S_ASC_DSC/5DAE)
Raw code: 5DAE
ECU: ABS/DSC
Status: Pending fault present during this driving cycle, Validated and stored in non volatile memory, Validated fault has been present during this drive cycle

============9==============
A8AD (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/A8AD)
Raw code: A8AD
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory

============10==============
9CB6 (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/9CB6)
Raw code: 9CB6
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory, Validated fault present at time of request

============11==============
A8C1 (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/A8C1)
Raw code: A8C1
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory, Validated fault present at time of request

============12==============
A8C0 (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/A8C0)
Raw code: A8C0
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory, Validated fault present at time of request

============13==============
A8B6 (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/A8B6)
Raw code: A8B6
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory, Validated fault present at time of request

============14==============
A8AA (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/A8AA)
Raw code: A8AA
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory

============15==============
A8AB (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/A8AB)
Raw code: A8AB
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory

============16==============
9CB4 (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/9CB4)
Raw code: 9CB4
ECU: Central module (in driver's footwell) (FRM)
Status: Pending fault present, Validated and stored in non volatile memory

============17==============
9CB3 (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/9CB3)
Raw code: 9CB3
ECU: Central module (in driver's footwell) (FRM)
Status: Pending fault present, Validated and stored in non volatile memory

============18==============
A8B1 (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/A8B1)
Raw code: A8B1
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory

============19==============
A8B0 (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/A8B0)
Raw code: A8B0
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory

============20==============
A8A8 (https://my.obdcloud.com/dtc_codes/bmw/view/FRM/A8A8)
Raw code: A8A8
ECU: Central module (in driver's footwell) (FRM)
Status: Test conditions are met, Validated and stored in non volatile memory, Validated fault present at time of request

============21==============
E72B (https://my.obdcloud.com/dtc_codes/bmw/view/IHKA/E72B)
Raw code: E72B
ECU: Climate/heater/Air conditioning
Status: Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request

============22==============
E72C (https://my.obdcloud.com/dtc_codes/bmw/view/IHKA/E72C)
Raw code: E72C
ECU: Climate/heater/Air conditioning
Status: Test is inhibited by other DTC, Validated and stored in non volatile memory, Validated fault present at time of request