O2 sensor fun

[botus]

Any experts.... bikes on 37k and the CAT sensors have only done 15k active life (but been in there all along)

the bike has had 4 years of being strange.... often seems ambient temperature related - when above 24C and it loves life, below it has days of running like an utter dog....

it all went wrong after an i-level update where it got a new engine map in 2018 (that was made available, but never put on this bike, some 10 years prior) - from then on in it never ran as well as it did on the old map - and in cold conditions was massively over-fueling...

turns out when the map is that updated they should clear the adaptions and the bike needs its CAT sensors in and the vehicle std - so it can re adapt across all weathers, temps, altitudes etc. to the new world... but coz I was running a PC3 that never happened...

Anyway, eventually put it to stock wiped the adaptions and it would be OK for 250 miles then go mad over and over....

then last week the terrible over-fulling idle came with a vengeance and stayed... Putting the GS911 on, the CAT sensors were operating but each doing quite different stuff and the short term adaptions were stuck on 15% too much on cyl 1 and stayed totally static

I knew the right pot has slight corrosion on two pins of the CAT sensor and remade those but the bike is still the same...
So I decided to try swapping the CAT sensors side to side - and the fault moves - so clearly one is not happy - but I can't work out which...

Got one replacement sensor so I could play quick - only two of the four pins get any continuity on all 3 sensors - on 200 ohms I get 0.6 on one original and on the secondhand part I picked up - but as I wanted to play fast it was an old part I could get locally that day - and so I might have 2 dead and one OK, or even 3 in different states of dying...????

Fitted the newer bit in left pot, started the bike and almost straightaway the 15% (now on cyl 2 as I'd swapped sensors) starts climbing down and the 0.7% on the other cyl 1 climbed. But then never stopped and it just reversed the fault (back to how it was the day before I stated to play musical chairs....)

that muddled my simple brain - as I'd suspected the right pot sensor died and I'd moved it to the left... I then replaced the sensor on the left with a replacement and cyl 1 went normal but cyl 2 went mad...

then I realised I actually have no idea which is cyl 1 - I always assumed its the left pot (when sat on the bike) - I couldn't locate anything on the internet, and then I may have muddled my brain again - as I took out whats now on the right pot and was going to refit (what would have been) its original sensor - I'd wanted to check if the resistance on these wires and it was showing a difference between each sensor where one is obviously dead... and I forgot which I was putting back ...

but what caused me to get muddled - was of the three, one original had a different reading to the other two (but no idea which was correct) - then once hot all three were reading the same - then one wasn't as it cooled, then did, then didn't... the one I now think is the worst sensor gets 6.5 not 0.6 ohms on 200 setting...(and came off the left pot)

in the end, on the right pot I put back the what I believed was the original sensor - but in reality put back the duff one I had just taken out... Now with the original right sensor, the bike has started to behave on both pots and the O2 sensor voltages and the short term trims as seen on the GS911 looked normal -

So I guess it was the original left sensor that had been dead all along and I got muddled - But if that's true cyl 1 would have to be the right pot and or BMW deliberately mess up the fueling pushing 15% more on the opposite cyl to the one where the sensor fails just to make the bike run stupid and confuse people?

either way if you disconnect a sensor the fueling goes to much better than a lying / dead sensor

 

[Santa-2512]

I'm curious as to why a bike model that was discontinued in 2013, has received an I level update? -

And by CAT sensors you mean Lambda probes?

just buy 2 new ones and be done with - that way you have a stable baseline to start from

 

[botus]

because there was one the dealers never applied from 2008.... because they never bother - they want you to have an unreliable, untrustworthy motorcycle - best bit about this was before I understood the tech and the game they play - just 6 months after it was released - I was asking the dealer surely there must be a later map that runs better ? "we are BMW we don't do that sort of thing" was they lie they told with total authority - and I believed it till 2014 when car nerds told me to get mine sorted - my twin turbo nutter BM car got it first ever update and went twice as fast, the gearbox changed properly and it did 3mpg better afterwards

GS update from mid 2008 - ZFE, cluster and engine map updated

lots of fixes, the ones I remember
including safety circuit logic for the side stand
errors for TPMS
errors for fuel trip computer
on the engine
cold start fueling
idle stability
reduce engine knock

just forced them to do my k1600 - another cluster update between last year and this year.... that's 8 of the 13 modules that have been updated at least 3 times each - ones on 5 updates and only 2 that still run what they left the building with - ever since cars and bikes got software - its mostly a far bigger joke than the twice a month updated rubbish we get from microsoft - I'd wanted then to do it - as on that bike in the USA is a Stop Sale recall for safety systems that forgot to turn on in software.... All 2017 to 2022 F750 800 900 S1000RR and the K1600s have various rider mode safety features they just noticed they forgot to turn on correctly...

best one is the S1000RR anti-wheelie - becomes random if you have been playing a certain way in cluster menus - can just imagine the amount of children flipping them down the road as they have never had to understand throttle control before

 

[botus]

O2 sensors is the BM name....

I wasn't sure if it was the wiring (as I had that corrosion issue) or the ECU.... we had another guy spend ages on sensors and broken wires and it the end the bit that threw him was his ECU died (common on BM ECUs - same part is used on the cars !!! when you check forums) - So I wanted to see if I had just a sensors issue - looks like I did - but that would suggest for two years its been intermittent ??? rather than the heater circuit just died, like they mostly do on 9 out of 10 CAT sensors across all vehicles

 

[seahorse]

Cylinder 1 is the opposite to what you would expect i.e r/hand as you sit on bike. Had me foxed at first also.

 

[Steptoe]

As stated in post above. Cylinder 1 is on the R/H side.

 

[botus]

thanks guys

so the left sensor was dead. And it made the right pot (cyl 1) go super rich - this left sensor was also the one I disconnected after 2 days of it running horribly, and it went back to running far better - interesting trick by BMW ?

 

[Mistacat]

If using a stock headers with a balance pipe, a miss fire ( ignition/ rich) on the right cylinder will also be picked up to a degree by the left lambda sensor.
Not a problem if using aftermarket headers without a balance pipe.
Just something that is easily overlooked.

 

[Steptoe]

Not a problem if using aftermarket headers without a balance pipe.
Just something that is easily overlooked.

Do you enjoy having a shit lumpy idle and a flat spot in the silky smooth rev range

 

[Mistacat]

Do you enjoy having a shit lumpy idle and a flat spot in the silky smooth rev range

I was not recommending that folk should do away with a balance pipe on a stock system, Just that it is often overlooked that a bad coil on one side can influence the other cylinders lambda sensor.
As It happens I do not use a balance pipe and enjoy near perfect fuelling running an air fuel ratio of 13.8 to 1 with the help of the AF-XIED`s and verified by a dual channel Innovate LM2 with wide band lambda sensors mounted close to the stock narrow band sensors.

 

[Steptoe]

I was not recommending that folk should do away with a balance pipe on a stock system, Just that it is often overlooked that a bad coil on one side can influence the other cylinders lambda sensor.
As It happens I do not use a balance pipe and enjoy near perfect fuelling running an air fuel ratio of 13.8 to 1 with the help of the AF-XIED`s and verified by a dual channel Innovate LM2 with wide band lambda sensors mounted close to the stock narrow band sensors.

You’d get the same effect and a lot cheaper with a balance pipe. But admittedly, it wouldn’t sound as impressive telling everyone down the biker cafe

 

[Gelandestrasse]