O2 sensor eliminators aka fuel dongle?!

[randomdude]

Hello fellow fiddlers,

I know, the -decat headers=>enrich mixture- topic has been beaten to death by now but I just came across this product :


https://fueldongle.es/en/products/fuel-dongle-pp-20?rq=md_yamaha~mk_xtz-1200-super-tenere~xk_2011&fbclid=IwAR1mSVvpKVXPQY-7QiR5g9P7uNSBMnryU2FHtn05ET8mwaL-sjWb3Z5boF4

Well my question is: I want to swap the stock headers of my 1st gen -12 S10 to the decatted ones from Arrow, however I'd like to avoid going down the piggyback device route such as PCV, AT, PV3 etc.
Is there anyone who knows if I could get away with just the O2 sensor eliminator in order to skip running too lean and therefore end up having surging, hunting or backfiring at deccel after the swap?

If I get it right, the manufacturer claims that the eliminator will enrich the fuel in the st. mixture, as well as optimise the AFR by fooling basicaly the ECU to only use the default maps instead of relying upon the lamda sensors which inherently make the engine run lean in order to follow EU emissions. Something like the Booster plug or Rotweiller's fuel dongle for those who are familiar with KTM's.

I'm aware that this won't be an optimal solution as far as performance goes(such as dyno runs etc) but at least I would like to free up the motor, allow it to breath without making it a big deal. So, is it safe to put on the arrow headers and just eliminate the o2 sensors?

My current set up is , ECUnleashed II mapped for an Akrapovic muffler, K&N airfilter (1st gen -12)

Thanks in advance!

 

[siroco]

Hi, I have the fuel dongle in my ST. Great difference. Go for it

 

[randomdude]

Thanks, I have already ordered one, but I want to investigate a bit first if it's good in the long run. Do you have the Arrow (or any other decatted) headers and do you know if your bike runs rich or lean?

Also do you know if the fuel dongle copes well with a re-flashed ECU?

 

[Jlq1969]

more or less, this is what an o2 sensor emulator is

 

[randomdude]

View attachment 94721
more or less, this is what an o2 sensor emulator is

Interesting to see, I do realize that it's a simple device but my main concern is still about cancelling the O2 sensors above all.
What's the general consensus as for their function, are they only there to adjust the fuelling in order to pass emission tests or do they serve any other functional purpose? '
I 've read several contradicting theories about it. It seems that some people here even get smoother running bikes by unplugging o2 sensors after exhaust mods

 

[Jlq1969]

The O2 sensors only make the mixture more efficient, at idle….and up to a few rpm above this….from there, the sensors stop correcting the mixture and it is regulated by the rpm, position of the throttle butterfly and the vacuum sensor. Smooth?…yes…surely, but you will notice that it smells like poorly burned fuel, you will notice soot in the exhaust. The sensors have a closed circuit/loop. They will always be trying to get the mixture right (at idle and up to half throttle). With a reflash or with an o2 sensor emulator, you open the circuit, and leave the mixture with a fixed value and the sensors will no longer correct that. As the sensors work well only when they are hot, the ecu “allows” certain erroneous values during warm-up….and that is what the emulators do….the signal sent by the ecu to the O2 sensor, they return it to the ecu, as if sensor was cold. If you simply disconnected the sensor (without reflash or without emulator), when the ecu did not get a signal return, the check engine light would turn on

 

[randomdude]

JIq1969, thanks a lot for taking the time to explain, your post is very informative.

Notes: If I get it right, the ECUnleashed II reflash still utilizes the O2 sensors. I get no warning light on my 1st gen bike when I unplug the sensors.

Am I going to notice poorly burnt fuel and soot by having an O2 sensor emulator plugged in, too? Is that going to have ill effects on the valves?

It sounds to me that the 02 sensors are not suberbly efficient, taking in counts all the parameters (when cold etc)

The specific brand of the o2 emulators that I linked above, claims that they set the mix a notch down to 13.8 instead of 14.7. Would you recommend using such an O2 sensor emulator to compensate the fuel for the increased back pressure of a free flowing arrow header pipe?

questions, questions, I know..

 

[Jlq1969]

there are 2 fault codes regarding the O2 sensors…24 and 68….if when you disconnect the sensors, no fault codes appear…so your reflash must have opened the circuit, and the O2 sensors are inactive. If your sensors are inactive…it makes no sense to put an emulator….
The rich mixture, just to eliminate the O2 sensors…it is only at idle and half throttle….from there to full throttle….the O2 sensors would no longer act on the mix….If you want to enrich the mix “up”…. the reflash (on the software side), is indicated: more injector opening time, higher fuel pressure, or both

ECUnleashed Gen 2 reflash- What is does and how to get it

1. Is there a new Gen 2 flash for the Super Tenere? YES, we have updated our reflash for the XT1200. It is more of an evolution of the first flash then a radical change, we have worked hard to smooth out the throttle even more and have been able to eliminate the symptoms of the closed loop...

yamahasupertenere.com

 

[randomdude]

I get what you mean but to be honest I'm still a bit confused because in the same thread a few pages after, the ECU guy states this (last paragraph):

Yes, we can flash any market ECU



I'm going to try to clarify this without adding more confusion.
1. Yes, the O2 sensors are utilized unless removed.
2.A- ALL bikes with an aftermarket fuel controller, be it a PCV or Bazzaz, etc MUST be set to a ZERO map after the reflash. Because we change the ignition and fuel maps inside the ECU the 'stock' reference settings these maps use to adjust fuel are completely incorrect and will cause the bike to run incorrectly. Your fuel controller will still work after the reflash, but you will need a totally new map created by a tuner.
B.- Yes, you could remove the PC after the reflash, although it is not necessary. I would personally leave it installed so that the bike could be fine tuned after the reflash.
C. Yes as we do correct fueling with the flash



Significant improvements to the throttle response in "S" mode maps
1) Greater fuel efficiency in "S" mode maps
2) "T" mode mapping remains stock but we made slight adjustments to the AFR (Air/Fuel Ratio) in 5th and 6th gear producing a value of 13:1 as opposed to 12.7:1(factory)
3) Better advance maps over both cylinders 1 and 2
4) Fully compensated for the closed loop routine below 5k rpm
I'm under the impression that #'s 1,2,4 sound as if they're strictly fueling changes. Correct? I can see where that's a good update for folks if they won't be running a 3rd party fuel management system like a Power Commander or Bazzaz.
Can you elaborate a bit more on #3? Are you referring to timing map changes? If so, what scenarios would it be "better" (i.e. what does better mean?)
Thanks in advance.

Yes, number 3 refers to ignition timing changes. Better in this case meaning smoother ignition maps for both cylinders.


Surely if they are using the sensor I cannot remove it, also are they not just narrow band sensors in which case they cannot be utilized regardless of how you alter the mapping.
Please see the attachment** for this. They are not narrow band sensors as you can see they give a voltage reading all the way through the power band. What we do is alter the 'base' fuel maps, from there the ECU will use the O2 sensor to make minor fueling changes depending on the sensor readings, in this way our reflash utilizes the O2 sensors. IF you have removed the O2 sensor, the ECU will just use our altered 'base' maps without modification. These maps are still much smoother and will create more power from then the stock maps but because the bike still runs without the O2 sensor, we do say they are not required although they are recommended. We do not remove the functionality of the O2 sensor in the reflash if your bike is not equipped, we only disable the dash code which leaves the option to install one later a possibility.


**The attachment is a 5th gear run from the gen1 flash and is only for reference on the O2 sensor readings.

 

[pooh and xtine]

If your bike runs well currently, just fit the Arrow headers with the O2 sensors. They're unlikely to flow so much more air to make a difference and I seriously doubt that they’ll give you the symptoms you describe.

 

[randomdude]

Yup, bike runs fine now and I wouldn't like to mess with that. I'll go ahead get the Arrows and see what happens, the spark plugs will tell. I also got a pair of those eliminators to experiment but primarily I'll try to keep to the O2 sensors. Thanks for the input.