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Discussion Starter #1
My bike has many mods, done by former owner. Among them the O2 sensor bungs are plugged. How would this affect performance? Anybody else have theirs blocked off?
 

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My bike has many mods, done by former owner. Among them the O2 sensor bungs are plugged. How would this affect performance? Anybody else have theirs blocked off?
Depends on the mods.
If still using unmodified factory computer, it just richens the mixture by telling the computer the engine is cold - like leaving the choke on with a carb.
That's often the first attempt when intake & exhaust mods are done & it's running lean.
Left like that, it will help cover lean spots, but mileage & performance are not great.
BUT... Most fuel controllers don't use the sensor feedback.
If it has a fuel controller like dobeck, LLoydz, power commander, etc, then they are just removed from the loop & the engine is tuned with the controller.

Is there a controller under a sidecover or under seat?

List out the other mods & it'll be easier to help complete the picture.

Sent from my XT1585 using Tapatalk
 

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What disconnecting the O2 sensors really does is keep the bike in the open loop mode full time... So... when you are cruising at a steady speed/light throttle the bike doesn't lean out to 14.7:1 air/fuel ratio. That's all.

The O2sensors don't do ANYTHING until the bike is fully warmed up, because the bike won't close the loop on a cold engine.

I am telling you that 75% of all the **** you read on the internet is wrong.
 

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Discussion Starter #6
So why do so many remove them and plug the bungs? I think I'll consider re-connecting them, as it would seem counterproductive to disconnect them.
 

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So why do so many remove them and plug the bungs? I think I'll consider re-connecting them, as it would seem counterproductive to disconnect them.
You need to get the seat off & possibly the tank to see if there's a controller in there someplace.
You've posted a few questions.
Is it actually running ok right now?
Did it run ok when you got it?
Or it has run poorly since you bought it?
Did you buy it from a dealership where they didn't know the history, or bought it from the owner & can try to find out more about the mods & current setup?
With torque tubes, it would be pretty lean without some kind of fuel mod.

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Hooking up 02's will make your bike run lean at times. Lean condensation is what burns valves and more. Maybe over 87% of the guys unhook them so they have a richer running more witch can give you more power
 

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So why do so many remove them and plug the bungs? I think I'll consider re-connecting them, as it would seem counterproductive to disconnect them.
Most of the fuel controllers, until recently, require disconnecting the O2 sensors. Their input is confusing to the controller.

Look under the battery box or under the seat, that's where the steel frame bikes usually have a Power Commander mounted. If the bike has a VFC-III controller it will be under the right side cover usually.
 

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Discussion Starter #10
Bought it from a 3rd party who doesn't know the history of the bike, but somebody took very good care of it and added every accessory you can get. I runs rough at lower rpms, so I'm guessing with 19k miles it sat for a period of time and needs a good cleanout.
 

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I have to think that if someone has gone to the extent to put torque tubes on the bike then there will also be a controller to go with it. Possibly cams?
 

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No tuner on this bike. Pretty much runs like a ditch pump until you get the Rs up. Local shop wants $1k to Dyno it.
You're going to have to add a tuner & work thru tuning it, or bite the bullet & bring it to someone to someone (will still need the tuner for them to tweak also).

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