Alternate O2 sensor?
 

...for a 2004 R1100S. I got a price of $245 at the dealer, Yikes! I've never paid more than $40 for any other bike I've owned. I've even found alternates at a Ford dealerhip. Is there an alternate available? Or is there something special about this one?

What for? I had an 04' R1100S and I pulled the O2 sensor off completely and replaced it with a plug. There is a thread in here somewhere explaining how the Motronic defaults to a richer map when its not getting the signal from the O2 sensor. If you have done anything to make it breath better like a slip-on exhaust, you will actually improve overall performance by leaving it off. my $0.02

The bike is bone stock, except Ohlins and a K&N filter. It's been dyno'd and the AF curve is real lean. But there are driveability issues right now. It idles low and shaky and sometimes dies while sitting at a light. Sometimes it stutters under hard acceleration. When the bike is fully heated up, everything is fine mostly. But low speed parking lot manuevers are very stuttery. I've replaced the coil sticks, synched the TBs and the valves are in spec.

I searched and got results for everything but the actual O2 sensor. If it's another sensor that has issues, I don't know what it is. I haven't gotten into the BMW like I have with other bikes. So there's too much I don't know about it.

tehrte is an alternate available from napa or similar.

Moybin posted the part number a long bit back.

do a search again or pull the 02 sensor and go to the auto part sstore..you'll have to splice in the pigtail but they are an off-the-shelf item, usually like $60.00 or so...

Why do you think it's the sensor?
Pulling the cat plug isn't the wisest choice.
Another dumb blanket approach, though it does help in some leanness areas.

Just FYI, good luck getting the sensor unscrewed. I had my cat off a couple years ago and made an attempt to remove the O2 sensor just to take a look at it. It was extremely tight and wouldn't budge with a really big-ass wrench. I decided I didn't want to risk problems for something I didn't need to do, but if I was to try it again, I'd vise the sensor and turn the cat. This assume you have the cat off, of course.

Speaking of which, anytime you have the cat off, replace those rubber donut mounts. They get old/brittle, crack, and are occasionally implicated in weird vibrations and resonances.

Disconnecting the sensor at the tank and going for a test ride might yield some interesting data. If your driveability problems don't change, that's a strong indicator that you're barking up the wrong tree.

- Mark

I would like to suggest that you adjust the valves and sync. the throttle bodies. Chances are your bike will idle much better, and run much smother.

I had similar problem after buying a tank of premium in a very remote location. Had to leave the fast idle on around town or it would die sometimes. I was on a trip at the time and it ran that way for 6,000 miles. Back at home I removed the TBs and cleaned all the passages and the butterfly valves with carb cleaner spray. Remounted and everything was good again.

Here is the link to Moybin's sensor Number that I used. Cheaper and it worked.

http://forums.pelicanparts.com/bmw-r1100s-r1200s-tech-forum/212525-moybin-o2-sensor.html?highlight=sensor

I think Beemer Boneyard has new sensors for a very reasonable price.

Is there a test to tell how your O2 sensor is working? My 1999 has 50,000 miles and I ASSUME that all is well. But, I would like to check to make sure. However, is this necessary if all seems to be running okay?:rolleyes:

Well, this has been an issue for quite some time. Not bad gas, but I have to say it's gotten this way since the gas changed to 10% ethanol. It's been like this for about 2 years. However, none of my other bikes have been affected except for maybe 1 mpg less and ever so slightly less power. The BMW has gone down 5 mpg and is considerably less powerful.

2 BMW shops have looked at it and couldn't remedy the problem. 1 of them tried twice. They didn't do anything that I didn't already do. It became apparent that they really didn't understand these bikes. Compared to the many other bikes I've owned, the R1100S has been the most difficult to diagnose.

If there are any other ideas of what to look at, I'll give it a shot.

The O2 sensor has no role when riding on the map. When absent, it has no influence and Dobek recommends buying their Techlusion model that requires disconnecting the O2 sensor (providing the cat converter is gone). Whenever your O2 sensor is cool, it takes a mile or so to warm up; during that time it reads as if the A/F is radically lean but that never seems to bother the ECU.

I think it isn't wise to put an ohmmeter on the sensor. It operates like a little voltage generator, putting out a voltage around 1 volt or so max. If you carefully aim a propane torch at it, you can read the output with a digital voltmeter. My guess is that if it kind of seems to work, it is likely OK.

They do fail and most likely sooner than with a car. If you find a 4-wire sensor that fits physically, all are pretty much the same Bosch part internally. Try to do the plug splicing soldering as far from the sensor as you can. But you can buy new plugs (male and female) from the nice people at Dobek and they are cheap too - be sure you know which of the two plug models (fat one or cigar one) you need.

> The O2 sensor has no role when riding on the map.

Wrong. It tweaks to keep on target, over a small range, anytime you're not at heavy/WOT loads (i.e. purely on the map) Most of the time, one is on the map, AND, getting the effects of the sensor.

After the one tank of bad gas, my bike did not run right until I cleaned the TBs. Time would not have fixed it. Here in Seattle the gas changes for winter and I see a 10% drop in mileage for my bikes and cars.

I my case there must have been some sort of buildup between the butterfly and the TB. The buildup did not let enough air pass for a normal idle. Once the throttle was opened then it ran fine.

Good luck-

I guess I'll take the time to clean the TBs.

Anything else I should do while I'm at it?

Go find some gas sans corn oil. Clean the TB's and adjust the valves. Then do the Lycombing tune up (run the pi$$ out of it). Oh, and make sure the bottom plug is clean.

Looks like famous guru Brad Black ("Moto One") thinks you are wrong. Here's a quote from his published "Notebook" with some parts in-between removed:

"The information given relates to the Weber Marelli systems, covering all ECUs - P7, P8, 1.6M, 1.5M, 5.9M and Bosch Motronic 2.0, 2.2 and 2.4. The F650 BMS system will be much the same also. What follows is how the digital electronics go about making it all happen....

"Closed loop on BMW Motronic systems – 2.2 (USA mainly) and 2.4. the closed loop feature of the Motronic system is rather simple, but confuses many. This uses a lambda sensor in the exhaust....

"The signal from the lambda sensor is only considered when the throttle is held constant and the engine is not accelerating – on cruise basically. The ECU then uses the sensor output to either lean or richen the fuel injected....

"The closed loop is only in operation up to throttle openings of about 13 degrees it appears, so is only intended for use in cruise situations (most cruise at legal speeds is under 13 degrees throttle). It has no effect above this throttle opening, and certainly has no "correcting" effect over most of the fuel map....

"That’s it. I hope this report gives a better understanding of how the systems work."