Unplugging O2 sensors? - Victory Forums - Victory Motorcycle Forum
 
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post #1 of 8 (permalink) Old 07-19-2012, 02:38 AM Thread Starter
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Default Unplugging O2 sensors?

I have heard of people unplugging the O2 sensors on their bikes. What is the bennifit of this? Does it cause any problems?
I have a 50 state CA emmision 2009 Kingpin 8 Ball that is running too rich after a stage 1 re-flash would this help my problem?

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post #2 of 8 (permalink) Old 07-19-2012, 03:49 AM
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The point of unplugging the O2 sensors is to achieve a richer Air to Fuel ratio. Most do this because the factory AFR settings are set very lean in order to meet EPA guidelines.

If you're running rich you may have a bad ECU reflash, although it raises the question as to how you determined you're running rich. Typically even the stage 1 reflashes tend to be pretty lean and that's why people opt for putting fuel controllers on their bikes so they can have some control over the situation.

I am curious, however, how you determined your bike is running rich as that's a fairly odd situation for a factory setup.

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post #3 of 8 (permalink) Old 07-19-2012, 07:42 AM Thread Starter
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Quote:
Originally Posted by DunedinDragon View Post
The point of unplugging the O2 sensors is to achieve a richer Air to Fuel ratio. Most do this because the factory AFR settings are set very lean in order to meet EPA guidelines.

If you're running rich you may have a bad ECU reflash, although it raises the question as to how you determined you're running rich. Typically even the stage 1 reflashes tend to be pretty lean and that's why people opt for putting fuel controllers on their bikes so they can have some control over the situation.

I am curious, however, how you determined your bike is running rich as that's a fairly odd situation for a factory setup.
I am getting tons of black soot out of the exhaust. I was always told this means unburnt fuel. The bike backfires a lot too. I have even had a couple backfires from the intake side.
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post #4 of 8 (permalink) Old 07-19-2012, 09:55 AM
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Disco'd mine over a month ago. When tank is "highway" riding 55 - 70 mph with sensor's disconnected mpg's were 44.
Since I'd bought it new, same scenario was about 41 mpg with sensors connected and no passenger.
So I gained about 3 mpg's or 12 -15 miles on a tank. Throttle response is better, which probably explains why my mpg didn't change much or suffers in town.

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post #5 of 8 (permalink) Old 07-20-2012, 03:17 AM
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Originally Posted by shaggman View Post
I am getting tons of black soot out of the exhaust. I was always told this means unburnt fuel. The bike backfires a lot too. I have even had a couple backfires from the intake side.
This doesn't sound like something disconnecting the O2 sensors is going to fix. If you're truly getting backfiring (and not just decel popping) you need to get the bike looked at. It might be something as simple as a bad ECU flash, but what you describe sounds like it's more related to timing and spark advance than fuel mixture.

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post #6 of 8 (permalink) Old 07-20-2012, 04:20 AM
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Popping and coughing out the intake are signs of a lean condition... but excessive soot and black smoke too? Doesn't make any sense.

Soot in the exhaust is normal... even completely stock bikes have black inside the pipes. As long as it's not pushing out black smoke when you nail the throttle, soot in the pipes is not a sign that it's rich.

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post #7 of 8 (permalink) Old 07-21-2012, 04:00 PM
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Popping and coughing out the intake are signs of a lean condition... but excessive soot and black smoke too? Doesn't make any sense.

Soot in the exhaust is normal... even completely stock bikes have black inside the pipes. As long as it's not pushing out black smoke when you nail the throttle, soot in the pipes is not a sign that it's rich.
Popping can be cause by a lean condition but it can also be caused by to rich as well. The exhaust pipes load up with un-burnt fuel then that fuel gets ignited within the exhaust causing the pop. This sounds like your condition. Un-hooking the O2 sensors isn't going to help your problem. You either need to do a re-flash to correct the mixture or figure out how to get more air in with some intake mods. You're a little vague as to what your bikes set-up is as far as exhuast and intake mods so if you could provide more of that info you'd probably get some better answers for your question.

Last edited by 40XC; 07-21-2012 at 04:04 PM.
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post #8 of 8 (permalink) Old 07-23-2012, 02:01 PM
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when it blows black smoke, is it still cold? don't rev it cold
i've heard about and experienced this on my stage 1 KP, it'll roll coal if you rev it cold, it also use to foul plugs before i reset the idle(unF'ed it) and cleaned the throttle bodies,but yours shouldn't have this problem. where is your idle set?

its my understanding that the bike will overfuel if the idle drops to low, dont quote me on it though, i just read it long ago.

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