Motorcycle ECU flashing: Why disabling the o2 sensor is ALWAYS best

[@kx_shiro]

From my yesterday's dyno run I can say that in my case lambda could even f_ck up AFR at full throttle and low-mid rpm (up to 8k - past that we could get it mostly right). Also it was "smoothing" out the throttle response but in fact it made the motorcycle accelerate waaay slower and sluggish. Disabling it made a difference right away :) Great video!

[@aesoundforge]

Now it all makes sense! thanks!

[@vcyclenut]

Happy to help

[@cafeandfighters]

Thank you for finally telling us why we should disable the o2 sensor, 8min into a 9min video. Otherwise, I have enjoyed much of your content and may purchase products in the future.

[@vcyclenut]

Sorry. It was one of my earlier videos I made and I was still learning

[@JayWheelie]

Why would you bother complaining about something like this?

[@exothermal.sprocket]

Why do people have to be so rude. Even if you live to be 98 years old, you'll never stop learning. Learning takes patience and the ability to listen and keep attention.

[@vincentstrgar441]

Looking forward to when you can delve into the 698 Mono. Enjoying your airbox lid. Cheers

[@c10seth]

This was very helpful. Thank you. I do have some questions around eliminating the o2 sensors and changes in elevation; if you flash a machine and remove the o2 sensors at sea level, what happens when the bike is transported to an elevation of 5,000ft? Is the MAP/Manifold pressure sensors able to correct for this to understand the change in the barometric pressure? If you need to retunre for elevation and do not have access to a good dyno tuner, how would you approach this situation? I know tools such as TuneECU can log data while you ride, but without ARF, are you shooting in the dark to understand how to change a fueling or timing table? Is it worth hooking up an AFR gauge to the bungs in the exhaust to understand where it is while riding? I appreciate your help. I had an FZ1 with your tune on it and really enjoyed it. I moved a 2008 KTM Super Duke 990 R and I'm trying to understand all of the mods the previous owner had done.

[@vcyclenut]

This is all answered in the video.

[@JayWheelie]

Is it true that disabling the o2 sensor on the models with cruise control make the cruise control not work?

[@vcyclenut]

No. You just leave the o2 sensor plugged in and the cc works just like normal

[@JayWheelie]

@@vcyclenut okay cool. Any updates with the 2024 mt09 ecu? Will there need to be a new tune for that one?

[@vcyclenut]

@@JayWheelie yes. I released The 24 flash last week

[@albertohart5334]

What an educational video, thanks so much

[@vcyclenut]

Glad you enjoyed it!

[@albertohart5334]

@@vcyclenut could I ask, this is relevant to me because I’m thinking of putting an o2 eliminator on my bike (my o2 heater element measures in spec resistance but I have a code telling me it’s bad). When I put an eliminator on that won’t destroy the fueling right? I heard in an f9 video that bikes don’t use real time fuel mapping they just have a fixed map? But isn’t that fixed map dependent on the o2 sensor data

[@chipwood67]

Hi watched many mt09 flashes of your's on KZbin..as based in uk i have had to get my flash done over hear Yamaha mt 09 2022 gen 3 model euro 5... I was just wondering why my flash tune in uk. different ecu flashers in uk for example do different o2 sensor delete or not methods..i had mine turned off in ecu as i requested as i thought this is what you would do as standard i am running lv race decat baffle in and usual flash options done.. DNA air filter standard one.. you to have lv race on your mt i believe to Best exhaust in my opinion..my o2 has been turned off but I was told to leave it plugged in as It would throw a signal error..i have know error codes with it plugged in but off in ecu.. another flasher in uk said they keep the o2 sensor on and active with flash as if done correctly with flash it will run v good... I find this somewhat confusing.. with method or best option would be good insight..as your the mt guru.. thanks for any input...

[@vcyclenut]

my method is to turn the o2 sensors off

[@chipwood67]

Ok thanks for input.. O2 is off as I say but still plugged in to stop any errors codes I was told..👍

[@rathion2853]

Isn't O2 sensor feedback restricted to constant throttle applications eg: cruise? My understanding is that the fuel table will still be used for acceleration and low speed stuff where changes in throttle occur frequently. And then letting the O2 sensor come back in for stable RPM cruising won't affect how the rest of the bike feels, just maybe giving you some better fuel economy. Thanks for the video, been reading up on EFI.

[@vcyclenut]

Every bike is different but in general its steady state and light throttle application. The problem is many time it causes surging issues and an inability to achieve neutral throttle

[@rathion2853]

@@vcyclenut makes sense, thanks!

[@mptorecon]

If you have a flash, unplug the o2 and disable it. Bike runs great, what happens if you plug it back in?

[@vcyclenut]

Usually nothing but I have seen o2 sensors when they are going bad send such crazy voltages back to the ecu that it messes with the low speed running.

[@mptorecon]

@@vcyclenutroger that, I had a perfect running 23 ZX10R go in for valve adjustment, and now the bike is a turd. Went from wheeling in ever gear (204hp on dyno) to absolute turd and won’t go over 160mph.

[@vcyclenut]

@@mptorecon o2 Sensor doesn’t do anything at full throttle so not likely it , but can’t hurt to just unplug it from the harness

[@mptorecon]

@@vcyclenutthanks , I dropped it back at dealer that did the valve adjustment, didn’t think of it till after I left, so I don’t know if it’s the case just trying to figure out what they may have done wrong.

[@Scoot7827]

​@mptorecon hello! Did you get it back resolved? Riding season ina few mos. 🤜🤛

[@Cicurell]

I have a Yamaha MT 07 2024 euro 5,do you reccomend to disable the o2 sensor? I will feel any improvements?

[@vcyclenut]

How are you going to disable it?

[@Cicurell]

@@vcyclenut there is a kit that disable the o2 sensor,but i don't know if Is a good thing to do.

[@vcyclenut]

@@Cicurell not without tuning

[@Cicurell]

@@vcyclenut ok thanks for the tip

[@adjbob56]

Dave if you had a choice of buying & flashing MT 07 Euro 5 (with extra sensor stock) or a low mile 2020 MT 07 Euro 4 - which would you buy and flash? Consider both bikes have snorkel intake removed and aftermarket exhaust. It seems they changed very little with the 2021-2024 MT 07 but to comply with Euro 5 it appears to be a new ECU and harder valve seats.

[@moreandyanarchy9354]

my o2 sensor went bad on my ninja400, could I delete the o2 sensor without tuning it? or should I just buy a new o2 sensor if i’m not planning on tuning?

[@moreandyanarchy9354]

I have a full exhaust system as well if that changes anything

[@vcyclenut]

how do you know the o2 sensor is bad?

[@Mt09qc]

thank

[@planb2334]

14.7 is stoechiometric ratio (not ideal 13.1) . 👍

[@vcyclenut]

there is no one ideal air/fuel ratio