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Discussion Starter · #1 ·
So I decided to unhook the o2 & see if it would run better. For a little background my bike has never surged & always run great whether stock, with Spark headers & stock cans, & with the Spark headers & Arrow carbons.

It seemed a little lean around 4 to 5,00 RPM so I decided to see if the base map was richer. I unhooked the battery @ let the bike sit to drain the ECU's memoery then I unhooked the O2 sensor at the connector on the harness & covered both ends with electrical tape. Fired it up & it started easily & idled OK, not as clean as with the O2 but no surging or hunting. Once warm it seems to feel identical to the O2 plugged in setup. Temps were the same, throttle response same, & still some popping at part throttle around 4 to 5 K.

Again, my bike has never surged with any setup so I was curious to see what it would do with the O2 sensor unplugged. No difference for me so I now know I'll need a custom map & a PCIII to really get the most out of my Arrows & have piece of mind that I'm not running too lean. I'm going to do a baseline dyno next week so I'll do a run with the O2 sensor connected & one without & I'll post the results as well as the A/F readings..
 

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If you've got the time and are interested enough, have a read of this:

http://www.moto-one.com.au/performance/open_closed_loop_efi.html

particularly the "Adaption in use" section about 2/3rds of the way down. It talks about how the BMW R1150R takes 2 or 3 "commutes" to settle the adaption table down after it's been re-set. Assuming the Ducati EFI works similarly, I suspect that back to back dyno runs first without the O2 sensor, then with the O2 sensor _probably_ won't actually tell you the whole story. I'd probably try to arrange to ride the bike for an hour or so in the likely sort of use that'll have the computer setting the adaption table (constant low throttle opening, low to medium rpm operatiion) before running the "after" dyno runs...

big
 

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Discussion Starter · #3 ·
Excellent point [thumbsup] Brad's report is awesome & I'll make sure to hook up the O2 sensor & ride it around this week & then do that dyno run 1st.

I wonder if it's safer to run open loop as it seems richer. It definately smells richer @ idle :D Rich, loud, man the neighbors love me >:D
 

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GusDuc said:
I'm going to do a baseline dyno next week so I'll do a run with the O2 sensor connected & one without & I'll post the results as well as the A/F readings.
That should be very interesting. I know my S4R with the default program "smells" more like my old 996 when idling, which adjusted DP ECU and Termis and didn't run lean. With the sensor connected, it smelled like a new car idling. Very scientific, I know. :)
 

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Discussion Starter · #5 ·
Did some more unpluged riding today & it idles worse when cold & once warm runs fine but seems to dip below 1k when coming to a stop. It doesn't stall but it feels like it might momentarily. Temps seem to be the same as with O2 sensor installed. I could realy smell the exhaust @ the traffic lights. I think it actually runs better @ idle & below 5K with the O2 sensor hooked up.

I'll still do the dyno runs next week & see where I sit.
 

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cool info

is the bike showing and codes?

has anyone installed a powercomander yet?

if so which one ?

thanks
 

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After reading this thread, I decided to try a little test with Larakat's bike to see if just reseting the ECU's map table before plugging in the O2 censor would eliminate the surging. I was mostly curious since her gas mileage since we had originally posted up in the "Hunting" thread is averaging around 40mpg +/- depending on how she's riding and where - yes, she does ride agressive and likes to keep it in the power band ;D - All I can conclude is that our experiment succeeded in proving that the O2 censor just won't work for her bike.

1st Test:
  • 1. Plugged back in O2 censor at the previously unplugged connectors by the upper cylinder
  • 2. Unplugged battery and and turned bike "On" to reset the ECU's map table (NOTE: doing this drains any residual electricity from the capacitors)
  • 3. Plugged battery back in
  • 4. Started bike up and let it warm up for a couple minutes
  • 5. Quick test ride around

Results:
Bike started and sounded slightly "chuggish" (and not like the normal cold idle start up either). After a minute or two of warming up, the idle cadence started to change and it would fluctuate from around 800 rpms to around 1400 rpms. Almost like it was doing its best to try and stay alive. After letting it go through this cycle for another minute or so, Larakat got on it for a test ride. When she pulled away, I saw her immediately shaking her head in disgust. As in "Nope, this sucks and aint workin!". She took a couple loops around the block and pulled back in. She expressed that she noticed the surge right away and a further comment of: "It felt like ASS! Unstable, unworthy and unsafe. The only way to make it work was to run it in a very high RPM range, like some Yamaha 4 cylinder. F**K that!!! Even then, it still didn't feel right."


2nd Test:
  • 1. Unplugged O2 censor at the connectors by the upper cylinder
  • 2. Unplugged battery and and turned bike "On" to reset the ECU's map table
  • 3. Plugged battery back in
  • 4. Started bike up
  • 5. Quick test ride around

Results:
Started up like it should and immediately settled into a nice 1200 rpm cadence. The bike makes such a difference sound when the O2 is unplugged. It really sounds good and has a deeper, throatier tone to it. She threw it in gear and there was no bogging or hesitation to it. Very snappy. After her couple hot laps around the block, she returned to proclaim "Creamy, sexy smooth!".

Conclusion
I'm honestly baffled as to why this trick is not working for all those that are experiencing this problem. Maybe it has something to do with our sea level living conditions. all I can say is that Larakat's bike runs better AND cooler than it does with the censor plugged in. I attribute the cooler running temps to the richer conditions. Also, being in the Tampa, Florida area with the brutal sun and temps, I find it rather important to keep an air cooled engine running as cool as it can.

We have also checked her plugs by running the RPMs up to around 6000 RPMs while riding and then hitting the kill switch and letting it role up to the garage. Doing this will show the plugs as they would look under operating conditions. The plugs look excellent!!! Not a sign of overly rich at all.

All in all, for those that are still experiencing this issue and you have not tried to unplug the O2 censor, try the above steps. It might help you out. Then again, it might now.
 

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Hi,
just some questions about the 02 sensor and the closed loop system. When I bought my bike in July I talked to a local ducati mechanic about the system. He said that the stock ecu has a co trim but there's no use to trim it because of the o2 sensor(the sensor transmit information to ecu and the trimmed setting is being reset to normal) The question is, what about the o2 sensor removed?Any experiences, or is this unthinkable? :eek:
 

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Jake82 said:
Hi,
just some questions about the 02 sensor and the closed loop system. When I bought my bike in July I talked to a local ducati mechanic about the system. He said that the stock ecu has a co trim but there's no use to trim it because of the o2 sensor(the sensor transmit information to ecu and the trimmed setting is being reset to normal) The question is, what about the o2 sensor removed?Any experiences, or is this unthinkable? :eek:
Read my above post ;)
 

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Jake82 said:
Hi,
just some questions about the 02 sensor and the closed loop system. When I bought my bike in July I talked to a local ducati mechanic about the system. He said that the stock ecu has a co trim but there's no use to trim it because of the o2 sensor(the sensor transmit information to ecu and the trimmed setting is being reset to normal) The question is, what about the o2 sensor removed?Any experiences, or is this unthinkable? :eek:
There is a trim adjustment for a reason. If trim is too rich or too lean it will cause surge and bad idle as since closed loop has to compensate over a wider range.
 

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I tried Conecting and unconecting O2 sensor, on Bike with full Arrow Exhaust don,t notice much difference anybody tried a resistor in-line with )@ sinsor
 

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Discussion Starter · #13 ·
gixracer said:
cool info

is the bike showing and codes?

has anyone installed a powercomander yet?

if so which one ?

thanks
No codes thown on mine. Again, I never had surging but I was curious to see if it would run better, richer, with the O2 sensor unplugged. It was richer @ idle but maybe to rich as it stalled when cold & at other times as well.

I'm planning on running a PC III with a custom map & no sensor once I find a good tuner ;)
 

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Hey Gyxracer, I have a pcIII on my 06 s2r1k got it from Fast By Ferracci. Someone else had it done here I'm not sure who it was. Bike runs great. I was concerned that it might be a bit lean so I disconected the OS. I'm going on a long ride this weekend I will post the reults when I get back.
P.S no codes
 

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The ecu reads a constant changing output from the O2 sensor from rich to lean to rich and so on.

I visited the boys at Pat Clark Motorsports who sell Ducati in Vegas. They said the boys from Dynojet have ben borrowing a S4Rs to develop their power commander for our bikes but there is no luck as yet. Dynojet has tried to emulate the output of the O2 senor but the ecu wont look at it.

So we will have to wait till someone hits the problem on the head.

Xerses, Did the engine light come on when the O2 sensor was disconnected?

Ozzy Rob
 

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DUCMONROB said:
...

Xerses, Did the engine light come on when the O2 sensor was disconnected?

Ozzy Rob
Rob,

Nope, no engine light. Runs like a top.

I test rode an 07 S4R today and I think Larakats S2R1000 sans O2 censor has much better low end grunt. I'm not sure I would be able to say that with it pluged in though. It just isn't the same bike with it plugged in (in a bad way). Our dealer today said the fix was to get an aftermarket exhaust kit!!! HAHAHAHAHAHAAA!!! Larakat loves it as is and actually loves the stock pipes. We may core the pipes and get a mid pipe to remove the bladder.
 

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It would be good to get the bike gas analised. You would check reading when you first do it then take the bike for a good 1hr ride then check it again. I`m saying this as with the sensor disconnected this shows a 0 volt output which tells the ecu it is either rich or lean so the ecu will compensate and give the motor more or less fuel.

Food for thought.

Rob
 

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DUCMONROB said:
It would be good to get the bike gas analised. You would check reading when you first do it then take the bike for a good 1hr ride then check it again. I`m saying this as with the sensor disconnected this shows a 0 volt output which tells the ecu it is either rich or lean so the ecu will compensate and give the motor more or less fuel.

Food for thought.

Rob
Rob,

Not sure I follow your thoughts. The bike has been ridden for probably a good 2000 miles with the o2 censor disconnected and has never fluctuated and has been running great. At this point, Larakat and I are not planning on doing anything. As the old saying goes, if it aint broke, don't fix it. It definitely isn't broke. [thumbsup]
 

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I have noticed that most of s2r1000 owners have changed the stock pipes. Arrows(full) are pretty popular, silmotor(with spark midpipe),zard(full) etc..So, the question is that are you driving the 02 sensor connected or..?Last week I fitted the spark midpipe, the o2 is connected and I think the bike is runnig better than stock!I could assume that it's a bit lean but.. :)
E:Anyone dynoed the bike with pipes etc and the stock ecu..Interested abuot the what the CO was?


The co 5,5 would be good
 
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