Bloody O2 sensors again!!!! Should have done a recall!!

Izice

Member
In the last year or so i've had x3 O2 lamda sensors changed.

This is my OBD2 reader codes leading to it's 3rd time in the stealers with o2 sensor issues.

Tuesday 20th

P2629 – O2 Sensor pumping current trim circuit/open ( Bank 2 Sensor 1)
P2415 – O2 Sensor exhaust sample error (Bank 2 Sensor 1)
P2414 – O2 Sensor exhaust sample error (Bank 1 Sensor 1)
P2626 – O2 Sensor pumping & current trim circuit (Bank 1 Sensor 1)

After DTC reset of all codes and trip to work.

P2195 – O2 Sensor signal biased / stuck lean (Bank 1 Sensor 1 )
P2629 – O2 Sensor pumping circuit trim circuit / open (Bank 2 Sensor 1)

Another reset DTC no faults or EML on took a drive to work and tested again.

P0171 – “Pending” system too lean Bank 1
P2626 – O2 Sensor pumping circuit trim / circuit open (Bank 1 Sensor 1)
P2629 – O2 Sensor pumping current trim circuit open (Bank 2 Sensor 1)

Drove home and EML came on. Monday 26th - into bmw garage 28th pm

Cars now in at the stealers for it's second day. Got an update call today to say that the boys in the workshop had changed a sensor and the service manager said that " we usually change all sensors when one goes".

Now this has set the alarms off in my head because when i initially went to this garage (BMW) i tried to get them to replace all the o2 sensors because i read somewhere that by changing just the one can make the others go bad. I tried this as the car was still under approved used warranty and the same service manager refused and said we just change the one indicated as showing faulty in the diagnostics.

Now needless to say the car is now out of warranty and the sods telling me this. I reminded him during the call that i did stated this when i first brought it to that garage 6 months ago. The guy also said the ECU would need reset.

I explained to him that this should be done as a matter of fact each time a O2 sensor was replaced and again doubts were raised whether they did this last time it was in.

Anyways im expected a hefty bill and a Z4MR with ongoing O2 faults due to mechanics who don't know what their doing. :headbang:

I'll let you know the outcome.
 
And our O2 sensor sometimes throws an exception which when ignored goes away after three duty cycles. Why not ignore them?
 
Yeah they gave me the pish that they only change what fault is indicated under the warranty....now they are clutching at straws and have no idea hence angling at all sensors needing done.

I would ignore them (fault) normally but its a bit lumpy on cold start and perhaps mpg is down a bit......end of the day i want the car right.

Another option may be a remap to remove/delete the O2 sensors and so gain performance and loose the continuous rolling fault of O2 sensors. The fault might not even be the O2 sensors perhaps an air leak on the exhaust sytem...they didnt even mention checking this....blinkered into fault diagnostic machine and changing what it indicates without thinking.

I'll see what happens tomorrow.
 
Spoken to BMW UK?

I can't imagine they fail that often.. considered it might be something else? Have you got proof they've been done regularly/recently that you can show to BMW?

Where abouts are you based, maybe we could recommend a better garage?
 
CornishRob said:
mmm-five said:
Strangely, I've never had any of the 'common' O2 sensor or rear spring issues.

Surely what fuel people are using or how they drive must effect these sensors.

I believe it does, as must BMW as in the service book they are a scheduled change depending on what country you live in.
 
i crawled under mine and changed them myself, on my back while the car was on jack stands, i refuse to pay a garage for this stuff!! i won't lie, its not that difficult just time consuming, it took me a weekend slowly taking my time.
 
Managed to do 70+k miles in my previous Z4 M Coupe with no issues with these. I've read about people having reoccurring issues. I can only think the type of driving(short journeys?), the fuel used, or another problem possibly causing premature failure.
 
Most of the time o2 sensors go bad if something is wrong with the heater circuit. That is very critical for the O2 sensor. So with recurring problems you might want to do some measurements to that. Maybe you can find a glitch.
 
Type of fuel used is Shell V power only.

Daily commute approx 40 miles ...engine achieves temp and regularly receives an Italian tune up during this trip.

The history with regards to O2 sensors getting changed lies with the garage although last time i specifically asked for exactly which one was changed and recorded this. The part should be guaranteed for two years show it will be interesting to see what they say when the phone call comes today.

I will ask them about the "heater circuit" to see if this was investigated also.

Thanks for the replies.
 
I am 100% convinced it's fuel quality related, at least on mine. When I imported my M from the UK in 2009, I at first always used EKO (Greek oil brand) 100 octane fuel supposedly due to its quality, it took about 6 months to throw the first O2 sensor related check-engine light. I had them replaced, a few months later the same... I've since switched to regular 98 octane from whatever station is more convenient and its been about 3 years now with NO problems with the sensors whatsoever.
 
ga41 said:
I am 100% convinced it's fuel quality related, at least on mine. When I imported my M from the UK in 2009, I at first always used EKO (Greek oil brand) 100 octane fuel supposedly due to its quality, it took about 6 months to throw the first O2 sensor related check-engine light. I had them replaced, a few months later the same... I've since switched to regular 98 octane from whatever station is more convenient and its been about 3 years now with NO problems with the sensors whatsoever.

I might just try the regular cheaper petrol....if anything it'll save me money. :)
 
GuidoK said:
Most of the time o2 sensors go bad if something is wrong with the heater circuit. That is very critical for the O2 sensor. So with recurring problems you might want to do some measurements to that. Maybe you can find a glitch.

Yep, I have a suspected failure in the heating circuit of one or both of my pre-cat sensors. I have a rough idle on cold start up, i.e. lambda sensors are not giving correct readings until the temperature is in them (usually 60secs or so when the issue disappears). At all other times the engine behaves perfectly.

Annoyingly, seems buying 2 is the best course of action since sods law will say that whilst it is most likely only one has problems, you'll find it's both. £90 each or so I think :roll:
 
TomK said:
GuidoK said:
Most of the time o2 sensors go bad if something is wrong with the heater circuit. That is very critical for the O2 sensor. So with recurring problems you might want to do some measurements to that. Maybe you can find a glitch.

Yep, I have a suspected failure in the heating circuit of one or both of my pre-cat sensors. I have a rough idle on cold start up, i.e. lambda sensors are not giving correct readings until the temperature is in them (usually 60secs or so when the issue disappears). At all other times the engine behaves perfectly.

Annoyingly, seems buying 2 is the best course of action since sods law will say that whilst it is most likely only one has problems, you'll find it's both. £90 each or so I think :roll:

The service manager phoned to say the garage had changed some sensors all related to O2 sensors very vague.....they tested it today with no issues and are going to check again on Monday when it's cold.

Then the big ....sigh and how much?
Determined not to pay for any previous Lamda sensors that have been replaced as within 2yrs as covered they should be covered by parts warranty.

BMW charge more than £90 for lamda sensors, the pre i think is £250 and the post £450 due to having to take exhaust off cha ching cha ching.
 
TomK said:

The first 60 sec the lambda sensors don't work at all. That time the ecu is in open loop, so the sensors are not used and the ecu uses a seperate mapping.
You're running cams and maybe a tune, that's the cause of the rough idling.
I don't know how hard it is for a tuner to adjust the open loop mapping.

I have the same, with just the twinscrew the idling in open loop got a bit worse, but with cams even more (it can stall the first 30sec or so when its cold).

If the heatercircuit in the lambdasensors is non functional the ecu should give a code as it monitors the current output from the heater.
When the heaters dont work properly, or even with headers and an alternative place for the sensors, they can be damaged by temperature shock. For instance due to moist in the exhaust.
 
GuidoK said:
TomK said:
The first 60 sec the lambda sensors don't work at all.
Sorry I should have been more specific. There are no issues for the 1st 60s (whilst the secondary airpump is working), then as soon as that stops and the idle revs begin to dip the roughness appears. This stops after another 45s or so. Idle is then dead even, and as I said the roughness does not reappear. I'll add that yes this problem started after the cams were installed, however it was present both pre-and post map. I've put it down to a coincidence in the timing as we have checked that it can not be a mechanical issue. I've also spoke to another owner who has the cams in and does not get this issue.
However, it's strange as I am not getting any error codes thrown. I'm surmising that it is still functioning just not very effectively.
 
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