O2 sensor with EJK?

[pitapola]

I just have a relevant question. Is the o2 sensor really that unnecessary for the correct function of the bike that it makes it worth it to unplug it for that small affect it would have strictly on the green fuel zone?  
I really don't know much about the purpose of the sensor. If it's only for emissions it's not that bad, but I'm worried if it affects the overall function of the bike.

The factory O2 sensor makes the bike maintain a lean air/fuel ratio (AFR) of 14.7 which is an EPA emissions compliant AFR. The O2 sensor is reading the exhaust gas and the ECU adjusts the fueling accordingly to maintain that AFR during low engine load conditions (idle, low RPM steady cruise). If you were to observe your driving habits, you would likely find that the majority of your riding is at low RPM, and steady cruise while going through traffic, sitting at stop lights, highway cruising, etc. A bike will typically run hotter when running leaner, so we can cool the bike down by eliminating the O2 sensor and correcting the fueling. This also gives the bike more low end throttle response and torque.  
If we leave the O2 sensor plugged in, then we need to set the green zone to the 0% fuel change setting so the green zone is not adding/subtracting any fuel. With the O2 sensor connected, it will see the added fuel from the green zone and pull the added fuel back out. The green zone would continue to add fuel even though the O2 sensor is trying to pull fuel so this can create a conflict and on certain vehicles it will cause running issues. 
 
Riders who have disconnected the O2 sensor report that the abrupt engine breaking is minimized and seems to be an overall smoother ride.
It is perfectly alright to leave the O2 sensor connected, but it is recommended to set the green adjustment mode to a 0% fuel change setting which is 3.5 on the EJK.
 
Hopefully this answers your questions
Let me know if you have any other questions.
 
-TuningHQ

Thank you for your quick reply. You pretty much answered my question. The only thing I would like to ask is if the 02 sensor does anything more apart from the function you just described. So basically is it there just for emission control or does it have other purposes also? I think I've read that it also adjusts the fuel according to atmospheric pressure changes? For example, if you're riding on a mountain. 
So what I'm asking is this: I know what I'm gaining if I plug it off, but am I losing anything else other than cleaner emissions? My mechanic was a little skeptical when I mentioned unplugging it, that's why I'm asking.
 
Again, thank you for your time.

[tuninghq]

The O2 sensor does actually help make the catalytic converter catalyze optimally. By maintaining the lean AFR of 14.7, the cat is able to catalyze the unburnt hydrocarbons optimally. If the fueling is richer, the cat is unable to catalyze and basically goes dormant. This is another reason why the O2 sensor only operates at lowet RPMs. At higher RPMs, the exhaust gas velocity moving through the cat is too fast to catalyze effectively.
 
Your MAP (Manifold Absolute Pressure) sensor is the sensor that will adjust fuel tables for elevation changes. Atmospheric pressure changes with elevation, your MAP sensor will see this and adjust accordingly.
 
-TuningHQ
 
 

[Beemer]

For further peace of mind, I have an aftermarket pipe, an Akra c.f. and a Dobeck rep. told me that above 1500 rpm the EJK overrides the 02 sensor so leaving the sensor plugged in won't hurt a thing. That's how I run mine and it runs well.

[crsnhppr]

Idk for what it's worth I tried lots of combinations with the stock exu and o2
 
Stock airbox/ecu/drilled stock exhaust / 02 in: sounds better, sight torque decrease in low rpm, higher rpm high gear HO
 
Airbox snorkel removed / drilled stock exhaust / 02 in ; little more torque than last setup, engine wants to stall a little more at low rpm idk why
 
Airbox snorkel removes/ drilled stock exhaust /02 unplugged. Exhaust smell at idle more gassy , smoother /higher rpm at idle , cruising and normal acceleration has more bite and smoothness (slight)
 
Airbox snorkel removed and air filter removed with same as above , created a higher hp in the high end.
 
Tested in acceleration in all cases produced a marginally quicker bike
 
Bike was tested against a fz-07 that had 11,000 fewer miles , a rider that weighed 30 pounds less and was completely stock. My bike pulled ahead in all but the first setup mentioned. 3rd,4th,5th,and 6th gear pulls at 30,40,50,and 55 mph in good conditioned.
 
 
I should note I've replaced my engine oil every 1.5miles religiously and did a hard break in with the first 2nd and 3rd oil changes inside of 1500 miles (hard break in .. haaaaard, with spectero Dino oil, and fluctuated between Amsoil and Spector full synth since )

[crsnhppr]

All that again stock ecu and no ejk( I gotta ejk in the mail

[Bigle]

On 11/16/2016 at 5:29 PM, tuninghq said:

The O2 sensor does actually help make the catalytic converter catalyze optimally. By maintaining the lean AFR of 14.7, the cat is able to catalyze the unburnt hydrocarbons optimally. If the fueling is richer, the cat is unable to catalyze and basically goes dormant. This is another reason why the O2 sensor only operates at lowet RPMs. At higher RPMs, the exhaust gas velocity moving through the cat is too fast to catalyze effectively.
 
Your MAP (Manifold Absolute Pressure) sensor is the sensor that will adjust fuel tables for elevation changes. Atmospheric pressure changes with elevation, your MAP sensor will see this and adjust accordingly.
 
-TuningHQ
 
 

I know this is an old response but I have a quick question that I think you answered. I live in Calgary at 3600ft altitude, and I wanted to confirm (basically exactly as you said) that my 2015 fz07 is adjusting the air fuel at all times to account for this. 

I was hoping it didn't adjust for altitude and that the lack of air would help offset my full akrapovic exhaust but this seems to answer my question, so I still need a fuel controller.