O2 sensor question

[dave sawyer]

97 R1100RT 167K+ miles.

What are the symptoms of O2 sensor failure?

Any recommended replacement interval/mileage?

Thanks

[dirtrider]

Afternoon Dave

 

That is a lot of miles for an 02 sensor to go & remain sensitive.

 

The signs of a blatantly defective 02 is pretty evident if it is still operational but real lazy or slow to respond. Probably stalling at times, poor running at low throttle opening a few miles after ride off, engine runs good when cold but not so good after engine warm up, erratic idle, etc.

 

A fully failed 02 is difficult to tell on the 1100 as the engine will probably run & idle better than with a NON functional 02 sensor.

 

A slightly lazy 02 is very difficult to tell without instrumentation to show the cross over & voltage swing peaks.

 

Personally at your mileage I would just disconnect the 02 sensor & ride it like that. Or better yet, just remove the CCP as that forces the European open loop mapping & disregard of the 02 sensor.

 

As a rule, the BMW 1100 runs better with the CCP removed as that is a better map without 02 influence. At your mileage I doubt the cat is still performing up to peak performance anyhow.

 

[roger 04 rt]

+1

 

For RTs, no Coding Plug on an 1100 will give better fueling. I'm aware of an R1100RT owner in Texas who is going to add an LC-1 Wideband sensor. When he gets to it, I've asked him to run without a Coding Plug and log the AFR. At that point we'll have a good idea of what the R1100 does with the no-CAT map.

 

For anyone with a GS who reads this I believe that a 30-87a Coding Plug would signal that its a GS (87a) but without a CAT, meaning no connection from 30 to 86 or 87.

[kmac]

They often smell like rotten eggs as well when the O2 is bad. Not the best diagnostic method but it is a symptom.

[dave sawyer]

Thanks DR. I haven't noticed any running symptoms. Idles well, no stalling, mileage around 42mpg depending on how hard the throttle is turned. Returned 50mpg last year when I was mentoring a new rider.

I remember when the 1100's came out there was some discussion on installing the GS CCP in the RT, but I can't remember what advantage was claimed. I tried it, but don't remember any improvements. I presume removing the CCP, reverting to Euro specs, will decrees mpg?

I did install the GS intake tubes per advice of Paul Glaves, which was suppose to improve mid-range performance.

I also noticed on the last throttle balance the rpm would wander up and down when held at 3000 rpm as if searching for proper mixture.

Sorry, rambling.

Thanks for input.

 

[roger 04 rt]

Paul's advice to you was from a series of experiments run by a guy named Rob Lentini who documented a zero-zero, GS tubes on the RT and Pink (GS) Coding Plug. You can read about it on page 86 of Super Tune Up for R1100.

 

The work was done at a time when Wideband AFR dataloggers were not available and at a time when many riders wanted better driveability and less surging on their R1100RTs. Today, I think there's clear evidence that if you can find a way to add 4-6% more fuel you will get a better running 1100, than the Lentini Super Tune.

 

The only problem with the no-Coding plug approach is that if you're running fuel with ethanol it starts 4% leaner than gasoline and if you remove the coding plug, since you don't get any "learning" by the motronic on an Open Loop bike, you end up at about the same place.

 

The reason you end up at the same place with Ethanol, whether Open Loop (no Coding Plug) or Closed Loop with Coding Plug and O2 is that the Closed Loop program brings the lean ethanol fuel from 15.3:1 back to 14.7:1.

 

On the other hand, if you run ethanol on a bike with the European map that is about 4-5% richer but run fuel that is 4% leaner, you most likely only end up 1-2% better.

 

If you run ethanol and want the performance gains of a richer mixture, an Innovate LC-1 will get you their.

[dirtrider]

Afternoon Roger

 

A couple of points on the Ma 2.2 1100.

 

The 1100 (MA 2.2) can be richened up slightly more than design intent in open loop as the TPS is non learnable therefore can be nudged to increase the output voltage vs throttle plate position to richen the Alpha/n a bit over stock.

 

The big gain with running the 1100 Ma 2.2 with no coding plug is that significantly richens the idle fueling if no idle trim pot is used. That rich idle fueling carries up into the light throttle operational area (basically the major surging throttle opening area).

 

[dave sawyer]

I guess the original reason for my question was to see if I'd benefit from renewing the O2 sensor on this bike.

[dirtrider]

Evening Dave

 

No way to really know as we don't know if your existing 02 is operating correctly.

 

As I mentioned above it is not always evident if you have defective 02 or not. Unless you install a new 02 to compare the runability, or hook up a meter & observe the 02 output, then no real good way to be sure on the health of your present 02.

 

About the only thing I can tell you is, at you mileage, assuming you still have the original 02, there is a good chance it isn't as active as it should be.

 

If you want to retain 02 fueling control then, at your mileage, a new 02 sure would be a good idea.

 

But, as I mentioned above, most 1100's actually run better with no 02 & no CCP.

 

As far as that effecting fuel mileage?-- maybe lower maybe higher, possibly no difference. At high speeds the 1100 doesn't use the 02 nearly as much as the 1150 Ma 2.4 system does.

 

[roger 04 rt]

Afternoon Roger

 

A couple of points on the Ma 2.2 1100.

 

The 1100 (MA 2.2) can be richened up slightly more than design intent in open loop as the TPS is non learnable therefore can be nudged to increase the output voltage vs throttle plate position to richen the Alpha/n a bit over stock.

 

The big gain with running the 1100 Ma 2.2 with no coding plug is that significantly richens the idle fueling if no idle trim pot is used. That rich idle fueling carries up into the light throttle operational area (basically the major surging throttle opening area).

 

Good evening DR,

I'll grant you your points that the no-CAT coding plugs (no plug, 30-87a) are richer, likely throughout the range.

 

The unknowns are: what are the no-CAT AFR targets in the base fueling tables, is the CO Pot creating an additive or scaling factor, how does offsetting the TPS affect fueling, and if the CO Pot trim is additive (and since there is no O2 sensor learning) how is the fueling adjusted for long term aging of the fueling system and/or fuel mix (ethanol or none)?

 

Dave,

I don't disagree with any of DR's comments but if you run E10 gasoline, and you take DR's advice to pull the Coding Plug, you might want to try a BoosterPlug which would completely counteract the effect of ethanol.

 

The biggest issue with pulling the coding plug is that you lose the corrective Closed Loop functions of the MA2.2, whatever they are.

 

If you want to keep your O2 sensor, you can roughly test it with an analog voltmeter. Connect it to the black wire of your O2 sensor. Warm up the bike on a 10 minute ride and then watch the voltmeter's needle while the bike is idling, for a short time so it doesn't overheat. About every second it will swing between 100 mV and 800 mV repeatedly. That will tell you it is working but not how well.

 

Beemerboneyard sells a universal replacement sensor at a good price. Since your bike seems to be running well I wouldn't expect much if you replace the sensor.

[JamesW]

Hi Roger,

Don't forget that the EURO version of the R1100 is set up without coding plug and a 1K CO POT installed. At least that applies to my '94 R1100RSL which was manufactured in June '93. This is all detailed in the factory manuals I received with the bike when I purchased same. In '94 the only oilheads were the R1100RS and R1100GS with the RT still on the horizon. I am assuming the '97 RT with a 2.2 ECU would be configured the same as my '94 for EURO operation. As I understand it with the 2.2 ECU if the O2 sensor is disconnected the ECU looks for a CO POT.

[dirtrider]

Morning Roger

 

As James mentions, unlike the 1150RT, most European 1100RT bikes were built & sold without catalytic converters or 02 sensors. Therefore the Ma 2.2 has a REAL open loop fuel/spark map as there was no closed loop available to the non cat non 02 equipped bikes.

 

I have no idea what the open loop mapping gives as far as target fuel/air ratios either with normal gasoline or with ethanol (richer I can say, just not how much richer I don't know).

 

It is definitely rich enough as built to improve runability on most 1100 Ma 2.2 bikes over 02 controlled with closed loop mapping.

 

Because the 1100RT non cat, non 02 wasn't built or originally calibrated with an 02, I'm sure the open loop mapping must take that into account as there never would be any chance of closed loop (02) adaptives.

 

As far as the idle trim being additive?- I have no idea but the system is capable of going fairly rich at idle without the idle trim pot in place. As I mentioned above, that rich fueling at idle can carry up into the light throttle opening area a bit & that is where most 1100 riders have the light throttle surging concerns. The (Ma 2.2 non cat, non 02) system as built goes as rich as design allows with no trim pot in place & the trim pot is used to lean the idle fueling to meet the idle Co requirements of the country it was sold in.

 

As far as using a booster Plug on the 1100 Ma 2.2 system-- that would richen the idle fueling even more & without a trim pot in place that would more than likely leave an extremely rich idle (way too rich in my estimation).

 

If running something like an Intake Air Spoofer on the 1100 Ma 2.2 system I would highly recommend an idle trim pot be added (or made from a 10-20 turn linear 1k pot).

If fuel economy is a concern then an Intake Air Spoofer (Booster Plug) might not be the way to go as some 1100 riders did report significantly lower fuel economy with the CCP removed & no trim pot installed. But a lot of us back then did also tweak the TPS to tell the Ma 2.2 that the throttle plates were open a bit more than they actually were so a little more fuel was added because of that.

 

[roger 04 rt]

If running something like an Intake Air Spoofer on the 1100 Ma 2.2 system I would highly recommend an idle trim pot be added (or made from a 10-20 turn linear 1k pot).

If fuel economy is a concern then an Intake Air Spoofer (Booster Plug) might not be the way to go as some 1100 riders did report significantly lower fuel economy with the CCP removed & no trim pot installed. But a lot of us back then did also tweak the TPS to tell the Ma 2.2 that the throttle plates were open a bit more than they actually were so a little more fuel was added because of that.

Hi Jim,

My understanding is that even with an O2 connected it will trim with a CO Pot and run thenEuronmap if the coding plug says non-Cat.

 

Good Morning DR,

 

I appreciate that MA 2.2 and 2.4 are different, and thanks for continuing the discussion on this. I'm curious enough about how this works that I would be willing to assemble the parts of an LC-1 for the owner of a good running R1100 in the Eastern Mass area. That would make it a plug 'n play solution. All I would ask in return is the right to take some data, and for JamesW to make me up a CO Pot. Serious offer.

 

I fully understand the non-Cat models were designed to never have " learning ability" and therefore agree with the implications that either: a) the maps were rich enough to accommodate all the manufacturing tolerances, long term engine wear and fuel stoichiometry; or b) that the CO pot has a scaling effect that has the effect of being a whole map "adaptive". Given that some have reported poor mileage with no CO Pot, that would suggest that it is more likely a scaling factor than an additive.

 

The lack of TPS learning is interesting. The MA 2.2 has a calibration mode that can be accessed through the Diagnostic Plug that I've read about recently after I got some written material from Doug Raymod while working with him on the schematics. On the 1150 I've tried many times to get it to "mis-learn" the TPS by blocking the high and low limits of throttle travel after reset. No matter what I'd do, it still seems to come up with the right answers. On the 1100, even misadjusted its hard to think about a mechanism that would make the TPS voltage adjustment effect more than the very bottom of the range.

 

I'm not disputing any of the knowledge you have on the 1100s, I've never touched one. I'm curious though and would be interested in having some explanations for how its Motronic works. The 1150 gave up a lot of its secrets to the LC-1 Wideband data logger and the 1100 would too.

 

RB

[dirtrider]

Morning Roger

 

The 2.2 (BMW motorcycle) pot is basically an idle fueling trim pot to allow curb idle Co adjustments. In a lot of European countries there were idling Co requirements even with open loop mapping. If you look back at BMW requirements of that era, procedures & specs were only given for idle Co checking & adjustments. If the trim pot effected other fueling areas there surely would have been a checking procedure to verify those were correct or at least within a specified range.

 

Ducati & some other brands with early EFI addressed the idle Co concern with idle air trim screws or other mechanical idle Co adjusters. The carbureted models pretty well used the idle enleanment procedure of using the idle needles to do a lean idle drop or lean idle Co setting.

 

As far the open loop Ma 2.2 compensating for engine wear or fuel differences? I really don't know how much was designed into the fuel & spark mapping but some of that was automatically compensated for with the TPS input as a worn engine would need more throttle plate opening (therefore higher TPS voltage) to produce the same engine power of a less worn engine.

 

With the vehicle age & countries the BMW 1100 Ma 2.2 systems were sold in, I have my doubts that fuel alcohol content was even figured into the original mapping.

Fuel octane & it seems altitude were a factor as BMW offered CCP's to use alternate mapping in low octane countries & possibly higher altitude areas. Not sure if that only effected spark mapping or both fuel & spark mapping as a combined factor.

 

As far a outside data on the Ma 2.2 system-- you have to be very careful on where that data originates as there were quite a few Ma 2.2 automobile systems. I have some data on those (automotive systems) & they do seem to differ somewhat in operation from vehicle line to vehicle line & some don’t seem to match up to the BMW motorcycle usage on the Ma 2.2 computer. I have seen things written about the Ma 2.2 BMW 1100 that came from the automotive side & to me it doesn't seem to match what is really happening.

 

[roger 04 rt]

Good morning DR,

I take your point that there were mandated idle CO requirements but it is not beyond reason to think that Bosch engineers, knowing about Closed Loop adaptation, and having the CO Pot "dial", would have seen an easy step to a broader compensation of the fueling beyond idle. But I agree, without measurement, this is just speculation on my part.

 

The Diag Pin is labeled DPK, which I think is short for the German, "Throttle Position Sensor = Drosselklappenschalter, or possibly Drossel Klappen Position, = DKP, as shown on Motronic. Therefore DPE on Diag connector is probably Drosselklappen Position Einstellen = TP adjust, or calibrate." I put it in quotes because this came from Doug. The procedure I am referring to is described here and would seem much preferable to Lentini's zero=zero: MA 2.2 TPS Adjustment.

 

Regarding your point about wear being taken into account by a greater throttle opening I would say yes, but if the wear is lower fuel pressure, slower or lower flowing Injectors, those would produce an undesirable leanness that would not be corrected by TPS opening.

 

Roger

[JamesW]

Hello Roger,

I would help with CO POT but really it is simple. I just used the 9 turn 1K trim pot from Radio Shack for my 1100 and I sent Earle in Driggs, ID the same pot for his use. Earle's bike is a '97 RT and interestingly enough it had the connector for the factory CO POT as part of the OEM wiring harness but mine did not so I wired directly from the Motronic cable connector. Earle's 1100 responded really well to a tweek on the TPS. That was all it took to really calm the surging in his case after installing the CO POT and disconnecting the O2 sensor.

 

As far as the AFR goes on the 1100 without the O2 sensor connected my 1100 AFR did measure 13.8:1 last spring on the Big Twin (Boise) dino run. I'm good with 13.8:1. I have never played with the TPS on this bike as I am really satisfied with its performance other than it seems to require more cranking on cold start up than does my 1150RT. Suppose I could install my homemade BP on the 1100 just for fun but what D.R. said.....

 

 

[JamesW]

Roger, forgot to say thanks for that 2.2 fault diagnosis link. Definitely saved that file for future reference. I knew about clocking out the fault codes while watching a 12 volt LED but didn't know you could adjust the TPS. Most interesting.

[dirtrider]

Afternoon James

 

I must be missing something when reading that link. I see it as testing/checking for the fuel cut-off but to actually set & check the TPS voltage you still need to access the TPS connector & manually measure the TPS output with a voltmeter.

 

[roger 04 rt]

HI DR,

 

I read this:

 

Measuring the voltage between pins 1 and 4 at the TPS connector should indicate 0.375 Volts at the idle setting (closed throttle) with ignition ON engine OFF. Snap the throttle open/closed a few times to ensure a consistent reading. To adjust the TPS, loosen the two screws slightly and rotate the TPS until the temperature warning lamp (or the Test LED) 'just' comes ON at idle and goes OFF just above idle. If you are using a voltmeter, adjust the voltage to 0.375 at idle (closed throttle). This voltage MUST remain below 0.400 Volts at idle.

 

that it can be adjusted one of three ways and that the VM is an option. To me it sounds like getting the correct/incorrect signal from the Motronic is the preferred way.

 

What do you see/think?

RB

[dirtrider]

Afternoon Roger

 

On the 1100 Ma 2.2 system--I personally want the highest TPS voltage attainable but with a safety margin that POSITIVELY gives me under .4 volts at all (hot, cold, expanded throttle parts) closed throttle.

 

I have always found the .385v has done that with very few issues.

 

You have to access the TPS to get to the screws to adjust it anyways so why not get the voltage between terminal 1 & 4 at that time.

 

[roger 04 rt]

Afternoon DR,

That being the case, I think the voltmeter route is best for your approach. I haven't ever measured mine on the 1150 and what I'm interested in is what voltage triggers Overrun Fuel Cutoff.

 

For some owners, who may not have a DVM, the diagnostic connector could be better. Since the Motronic has an A/D inside it, it becomes its own DVM, referenced to all the other measurements it's making.

 

It might be that you could get the highest "legal" voltage by leaving the throttle closed, and turning the TPS to the point where it just comes on

[dirtrider]

Afternoon Roger

 

You can basically get that by setting the TPS to .399v but that doesn't leave any room for anomalies like heat growth of TB parts or throttle shaft to bushing wear, etc.

 

Back in the Ma 2.2 days we always set to a max of .385v as that seemed to always operate correctly.

 

[JamesW]

Yes D.R. I agree that if I want to adjust my TPS I would still just use my multimeter. I just thought that was an interesting method as described in that link. Just something that was kind of cool and a bit of interesting info. Haven't touched the TPS on my new 1100 because I like the way it runs.

[roger 04 rt]

Since the 1150 and 1100 use the same TPS sensor, perhaps they voltages are interpreted the same way. Here is what I just measured on mine:

 

Throttle Closed: 0.32 degrees, 352mV

Fast Idle Detent: 1.28 degrees, 509mV

Throttle Locked at 2 degrees (Overrun Fuel Cutoff): 647mV

Fast Idle Full Up: 3.82 degrees, (didn't measure voltage)

 

When I have a chance I'll tweak the TPS and see how much richer the mixture gets by measuring with my LC-1.

[dirtrider]

Afternoon Roger

 

The TPS on your 1150 Ma 2.4 is a learning TPS system. It learns the low threshold & high threshold then uses that for throttle position. You can set your TPS up (within reason) but it will just re-learn the low & high threshold over a short time & return to the same fueling.

 

The 1100 Ma 2.2 is a non learning TPS so uses the TPS voltage as received. If that TPS is set higher the fueling will get richer in the non 02 control areas. (again within reason)

 

Just see what your 1150 MA 2.4 shows for TPS on the GS-911 then re-set it it a bit higher & do a new-learn then see what the GS-911 shows. It should be the same. Just don't go over .390 volts or so on your TPS advance.

 

 

Added: I have quite a few trapped 1150 GS-911 data streams & they ALL show .32 volts for base idle TPS. These are for different bikes & both single spark & twin spark 1150 Ma 2.4 systems.

[JamesW]

Just for fun I went out and checked the TPS volts on my 1100 and read 375mv throttle closed so while I was at it I adjusted to 385mv. Don't have the red LED so didn't fool with that.

[roger 04 rt]

Afternoon Roger

 

The TPS on your 1150 Ma 2.4 is a learning TPS system. It learns the low threshold & high threshold then uses that for throttle position. You can set your TPS up (within reason) but it will just re-learn the low & high threshold over a short time & return to the same fueling.

 

The 1100 Ma 2.2 is a non learning TPS so uses the TPS voltage as received. If that TPS is set higher the fueling will get richer in the non 02 control areas. (again within reason)

 

Just see what your 1150 MA 2.4 shows for TPS on the GS-911 then re-set it it a bit higher & do a new-learn then see what the GS-911 shows. It should be the same. Just don't go over .390 volts or so on your TPS advance.

 

 

Added: I have quite a few trapped 1150 GS-911 data streams & they ALL show .32 volts for base idle TPS. These are for different bikes & both single spark & twin spark 1150 Ma 2.4 systems.

 

Evening DR,

 

I'll agree for the time-being that the 2.4 has a learning TPS and that it's different from the 2.2. Having said that I have set it up to deliberately mis-learn high and low ... but I've not been able to fool it.

 

The interesting thing about the data a couple posts back is that the TPS sensitivity is about 150 mV per degree, which means that 25 mV is only about 0.17 degrees. That doesn't seem like very much.

 

What I'm going to do is warm up my bike with the O2 disconnected, logging AFR, and introduce a 25 mV offset to the TPS, and see how much the idle AFR changes as i add and subtract the 25 mV. I see no reason for the 2.2 and 2.4 to be different in response to that input. When I have them, I'll post the results.

 

To your added, I have observed the same thing even when I deliberately mis-align. Unfortunately the 2.2 doesn't log these numbers on the GS-911 so we don't have a comparison.

 

RB

[dirtrider]

Morning Roger

 

That would be an interesting comparison.

 

To be meaningful you will have to do the TPS advance with no 02 fueling control during the tests (open loop). I'm not sure how quickly your Ma 2.4 system will re-learn the new TPS thresholds.

I will be curious if the 1150 Ma 2.4 gains idle RPM as the TPS is advanced then drops back to where it was after TPS threshold re-learn.

 

On the Ma 2.2 system it would also be difficult to track as advancing the TPS usually raises the idle RPM just a tad. Seeing as the throttle plates are still on the idle stops that RPM advance is either added fueling or added ign timing (or both).

 

Don't forget the TPS on both the 1100 Ma 2.2 system & 1150 Ma 2.4 system have a dual output TPS with a fine resolution for lower throttle plate openings & a second lower resolution output for wider throttle plate openings. That effects the mV per degree as the low output (TPS term 1&4 ) is primarily used only to about 1/2 throttle.

 

[roger 04 rt]

Morning DR,

 

As I said I've tried to fool the Motronic into learning the wrong tps values and it seems impossible to do. One possibility for the throttle rotation beyond learning the end points (and assuming that's what's going on) is that it is learning the best crossover points between the two potentiometers and/or learning the slope of each. Here is a link to what I think is the TPS Description, which shows a crossover at 23 degrees.

 

The test does need to be made Open Loop, but I don't need to rotate the TPS. I will inject a small current into the wiper pin which will add a voltage of 25 or so mV to the TPS signal. I'll monitor RPM, but will also log and monitor AFR. If boosting the TPS voltage by 25mV riches the mixture (or not) we will learn something.

 

I've started to realize that 25mV at idle corresponds to 0.17 degrees to the Motronic. Can so few degrees really change the mixture? We shall see! And is it 0.17 degrees at idle or does it translate to 0.17 degrees all the way up? Lots to find out ...

 

RB

 

 

[JamesW]

Hi Roger,

Why not just measure the TPS voltage before you start then adjust the TPS for the voltage you need then after the test dial it back to the measured quantity? Seems easier than inserting a voltage, maybe safer for the ECU as well.

[roger 04 rt]

There's no risk to injecting a small current and it means I don't have to play with the mechanical alignment of the TPS. That means I can make a more precise movement by using the electronic movement.

[JamesW]

Really, I don't think mechanical alignment of the TPS is an issue but oh well. If you just unplug the wideband from the bikes cable connector to disconnect from the Motronic you also disconnect the wideband heater wires. Maybe better to do it by way of your wiring junction box.

 

Ok, I'll shut-up and leave you to the experiment.

[roger 04 rt]

Let me explain a little more about my plan.

 

1) Disconnect the LC-1 from the Motronic so that even warmed up it won't go closed loop.

2) Set up to log AFR.

3) Warm up the bike to operating temperature and record idle AFR.

4) While running and recording, add 25 mV to the TPS signal, then add 50mV.

 

So that I don't stop the engine or otherwise change any condition, the 25mV will be added by adding a 200K resistor from +5V (pin 2) to pin 1. I'll be able to change that voltage by switching the resistor in and out very quickly. The AFR increase should be clear that way in the log. The reason for 200K is that the TPS protective resistor is 1K.

[JamesW]

Here's kind of a novel question. Before the motorcycle leaves the factory someone has adjusted the TPS. What I would like to know is how that someone does it. What is their procedure with a 2.2 or 2.4 ECU? I know that TPS adjustment is considered by BMW to be a big no no for the consumer. What about for the dealer?

 

Questions and more questions and s few answers. What is a body to do?

[dirtrider]

Morning James

 

I can't say for sure how BMW does it but I seriously doubt it is done at vehicle assembly level.

 

Based in how most similar TPS's are installed & adjusted in the automotive field the TPS would be installed & adjusted at the Throttle Body Supplier's initial assembly plant (probably Bing).

 

The throttle plate stop (plate angles) are set at the throttle body assembly so that would be an ideal place to also set the TPS.

 

That isn’t to say that one of the end-of-line performance tests at the BMW assembly plant isn't to verify the TPS is within specs as seen by the Motronic. Then if out of spec that bike would be sent to the repair area for adjustment before moving to the final shipment area.

 

[JamesW]

That makes sense D.R., thanks.

[Rx_Mich]

"Personally at your mileage I would just disconnect the 02 sensor & ride it like that. Or better yet, just remove the CCP as that forces the European open loop mapping & disregard of the 02 sensor.

 

As a rule, the BMW 1100 runs better with the CCP removed as that is a better map without 02 influence. At your mileage I doubt the cat is still performing up to peak performance anyhow."

 

Just some feedback on this... my 1996 R1100RT has 128K on it and was beginning to get rough idle and stall at traffic lights if I didn't consciously hold a higher idle than 1000 rpm. I pulled the yellow CCP module out of the fuse box and it immediately settled the roughness at low idle. Never a problem at regular speeds but idle in traffic was irritating making sure it remained lit. I will take a slightly lower gas mileage to remedy this situation without the need to replace the O2 sensor.

 

The other thing to mention is on very high milage bike, you may be pulling a bit of oil through the exhaust so even replacing the O2 sensor will be a short lived fix due to contamination. Better just to pull the CCP.

 

Thanks for your help..... again.