Is my Oxygen Sensor relevant or not?

[PADEROLIS]

Okay here goes... For a while I have complained about bad gas mileage on my 08, especially compared to other Busas. I've always said my 07 got much better gas mileage. My 08 has been running rich due to a leaking vacuum line that I recently found, I corrected it. I pulled all four spark plugs and cleaned the black soot that had developed on them, I also pulled the O2 sensor and cleaned it, I used a wire brush and brake cleaner. A mechanic friend of mine suggested I replace the O2 sensor because he said it may be damaged from the bike running rich so long, I don't have a check engine light on.
Also when Frank at PowerHouse flashed my ECU, according to my label, he disabled the O2 sensor. But if I unplug it, my check engine light will come on. So what does it mean that it's disabled? Does it still have an effect on my fuel/air system? Does replacing it make sense, or will I be wasting money since it's been disabled in the ECU flash?

 

[POWERHOUSE]

Don't worry about your O2 sensor, that has been disabled. Check your plugs again in a few hundred miles and see what is happening . . .

 

[PADEROLIS]

Thank you Frank!!! I forgot to add, when I sent you my ECU I had already installed a PC3, but I uninstalled it last week. I've read that the O2 sensor is disabled so it wont conflict if a piggy back fuel monitor (PC3 is installed). Now that the PC3 has been taken out; is it still ok that the O2 sensor is disabled?

 

[PADEROLIS]

This is what my spark plugs and O2 sensor looked like when I pulled them!

 

[POWERHOUSE]

why did you pull the powercommander out? I don't know what your set up is, but if there is any kind of pipe on that bike, the pc and a good tune would work wonders . . .

 

[PADEROLIS]

I pulled it out because I thought at the time, it could be causing my issues. The bike would start fine when it was cold. After the engine warmed up and I stopped somewhere, it would start and die unless I held the throttle open a little for a few seconds.
I’d also read that if you’re flashed, you don’t need a PC. In order, I installed the Muzzy’s 4 into1 full system and PC3, I sent my ECU out to you for the flash, after I reinstalled the ECU I had it tuned at a local shop. I know now that the PC3 wasn’t the issue, it was a vacuum leak. Should I reinstall the PC3? BTW, the bike is restarting a lot better now that I’ve corrected the vacuum leak! I just hope I see better fuel economy!

 

[POWERHOUSE]

If your bike was tuned on a dyno with that pc3, I would reinstall it. That stuff about not needing a pc with the ecu flash is not correct . . .

 

[PADEROLIS]

If your bike was tuned on a dyno with that pc3, I would reinstall it. That stuff about not needing a pc with the ecu flash is not correct . . .

Thank you very much, sir!! I will reinstall it tonight; much appreciated!!

 

[jellyrug]

This is what my spark plugs and O2 sensor looked like when I pulled them!View attachment 1582738
View attachment 1582739

View attachment 1582740

View attachment 1582741View attachment 1582742

It looks like you can drive a Hummer through that spark plug gap.

 

[PADEROLIS]

It looks like you can drive a Hummer through that spark plug gap.

They're iridium, I was told not to gap them because they were already pre gapped.

 

[mabupa]

Okay here goes... For a while I have complained about bad gas mileage on my 08, especially compared to other Busas. I've always said my 07 got much better gas mileage. My 08 has been running rich due to a leaking vacuum line that I recently found, I corrected it. I pulled all four spark plugs and cleaned the black soot that had developed on them, I also pulled the O2 sensor and cleaned it, I used a wire brush and brake cleaner. A mechanic friend of mine suggested I replace the O2 sensor because he said it may be damaged from the bike running rich so long, I don't have a check engine light on.
Also when Frank at PowerHouse flashed my ECU, according to my label, he disabled the O2 sensor. But if I unplug it, my check engine light will come on. So what does it mean that it's disabled? Does it still have an effect on my fuel/air system? Does replacing it make sense, or will I be wasting money since it's been disabled in the ECU flash?

For you to unplug the O2 sensor and not get the FI light, you would need to replace it for one of these.
https://m.ebay.com/itm/O2-OXYGEN-LA...-R-1300-Hayabusa-2008-2018-EL37-/330866352599
Granted, the only reason I bought an eliminator was because I didn’t put the sensor on my full R77 exhaust.

 

[ItsDooomz]

Must be a Gen 1 thing. You get no FI light on a Gen 2 with O2 removed from the ECU, no plug required.

 

[sixpack577]

Must be a Gen 1 thing. You get no FI light on a Gen 2 with O2 removed from the ECU, no plug required.

Gen1 does not have an O2 sensor.

 

[ItsDooomz]

Its been a few years since I've had a Gen 1, lol. I didn't have the FI light issue and I didn't use an O2 plug. I just removed it in ECU editor

 

[PADEROLIS]

For you to unplug the O2 sensor and not get the FI light, you would need to replace it for one of these.
https://m.ebay.com/itm/O2-OXYGEN-LA...-R-1300-Hayabusa-2008-2018-EL37-/330866352599
Granted, the only reason I bought an eliminator was because I didn’t put the sensor on my full R77 exhaust.

Thanks! I never knew about this.

 

[jermzfree]

Don't worry about your O2 sensor, that has been disabled. Check your plugs again in a few hundred miles and see what is happening . . .

Just curious what is the advantage of disabling the O2 sensor?

 

[POWERHOUSE]

Just curious what is the advantage of disabling the O2 sensor?

I am sure it is obvious to most that the introduction of O2 sensors on vehicles was not done for performance reasons, rather it is our friends at the EPA making our lives worthwhile. A stock O2 controls "closed loop" areas of the fuel map - targets the predetermined afr to make that vehicle "clean". It is no coincidence that clean rhymes with "lean" - because that is exactly what it does. I have seen stock O2s target between 14 and 15:1 air/fuel. Borderline lean misfire. Disabling the O2 gives the tuner the ability to tune that closed loop area and target the proper stoichiometry . . . better throttle response, smoother throttle, more hp and torque.

 

[jermzfree]

I am sure it is obvious to most that the introduction of O2 sensors on vehicles was not done for performance reasons, rather it is our friends at the EPA making our lives worthwhile. A stock O2 controls "closed loop" areas of the fuel map - targets the predetermined afr to make that vehicle "clean". It is no coincidence that clean rhymes with "lean" - because that is exactly what it does. I have seen stock O2s target between 14 and 15:1 air/fuel. Borderline lean misfire. Disabling the O2 gives the tuner the ability to tune that closed loop area and target the proper stoichiometry . . . better throttle response, smoother throttle, more hp and torque.

Thank you Frank. That was a very good explanation.

 

[jellyrug]

I am sure it is obvious to most that the introduction of O2 sensors on vehicles was not done for performance reasons, rather it is our friends at the EPA making our lives worthwhile. A stock O2 controls "closed loop" areas of the fuel map - targets the predetermined afr to make that vehicle "clean". It is no coincidence that clean rhymes with "lean" - because that is exactly what it does. I have seen stock O2s target between 14 and 15:1 air/fuel. Borderline lean misfire. Disabling the O2 gives the tuner the ability to tune that closed loop area and target the proper stoichiometry . . . better throttle response, smoother throttle, more hp and torque.

Frank, with respect, my Busa is 100% stock never felt the need to fiddle with it and no one else touches it, so I cannot comment on how the lambda sensor complements the ECU towards maintaining A/F ratio with a proper PID loop. Hard to believe Suzuki designed the system just to satisfy EPA and there is no compensation when riding from sea level up to 8,000ft elevation in Colorado. Then there is warm up of the motor as well as optimizing fuel consumption. As mentioned, I have not looked at this on a Busa, but have worked in the automotive arena overseas for two major German brands in FI development, including AMG where we use as many as four O2 sensors which form a critical part of the closed loop sensory system, including performance, fuel consumption and long term reliability.

I can also mention that I purchased a 600 Gixxer for track as a used bike with 9,000 miles on it and the previous owner had it tuned with a pipe and disabled the O2 sensor. I had to open the motor to de-carbonize, because A/F mixture was pretty bad. I took bike back to 100% stock with a stock pipe, replaced the O2 and the power increase was amazing. Again, no measurements, just relied on Suzuki's stock factory configuration. It made me wonder how long that extra hp the tuners get on their dino's last, once the bike gets back on the street with several miles under normal street riding conditions and no Lambda PID.

 

[mjl3truck]

I can't speak to all things Suzuki but with a Gen II the O2 sensor is there only to control the AFR at idle and just above. The sensor does not offer any input to the ECU beyond that. When you talk "compensation" it is done by the ECU taking in the parameters from the TPS, inlet air temp. sensor, air density sensor, GPS, etc. The ECU then looks up what the injectors need as far as fuel goes to maintain that parameter it is flashed at.
In many respects motorcycle ECUs are crude compared to cars. I'm sure there are bikes now running closed loop at all throttle openings but except for Harley I don't know of any running knock sensors as has been the case with cars for several years. Hell if you look around you can still buy a smaller 2018 bike with a carburetor on it, when was the last year you could get a carb on a car?
In my case I have my bike's AFR tuned for the fuel I'm running in Seattle area at 0 ft above sea level, dyno room at 65F. When I go to Bonneville where the DA can be 8000 ft. and 92F the ECU compensates based on its inputs to maintain the parameters I set in Seattle. Is it perfect, no. I log my AFRs with an Innovate LC-2 and make adjustments as needed but it is never more than 0.3 off fresh off the trailer. An amount that I think would not be noticeable unless you are splitting hairs.