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Discussion Starter #1
What purpose does the stock o2 sensor serve? It is after the catalytic converter, which makes me think that it isn't actually used for fuelling calculations.

Is the EFI on these bikes just open loop? Or does it actually have closed loop mode?

I can't find this info anywhere, any tuning gurus on here? Thanks!
 

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YZFR6... ooodles of HP
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It did not appear to do much on mine.nor could I find out the function.
 

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Discussion Starter #3
Mine is currently disabled with a flash from Bauce Racing. It ran fine for years, but now it wants to load up and foul plugs if you do a lot of idling and sitting in traffic, and I'm wondering if it's too rich since it can't trim out fuel.

Its not a HUGE problem, it goes through a set of plugs maybe once a year. It is annoying though. The last hiccup happened in the middle of a road trip 2000 miles from home. Nothing like your bike starting to run on 3 cylinders when you're on the other side of the country.

I have a wideband kit on the way so I can see what's happening.
 

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YZFR6... ooodles of HP
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Yeah, I suspected it only did something at idle/low rpm for emissions. The ais is open at low rpm to lean out for smog.
 

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Discussion Starter #5
That's normally when an engine will be in closed loop and target 14.7:1 AFR, but I don't know if this ECU has the capability to do that. If it's hanging out at 12-13:1 at idle then that's my problem.
 

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YZFR6... ooodles of HP
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14 at idle is even a bit much.. Haven't bothered to monkey my afr tables.
 

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Discussion Starter #8
Yes it has a closed loop mode.
Good to know. I guess I'll email my tuner and see about getting the o2 activated again.

I hooked up a wideband and went for a ride. Idle actually stays nice and close to stoich, but the rest of the map is all over the place. Cruising is very lean.
 

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Yes it has a closed loop mode.
Good to know. I guess I'll email my tuner and see about getting the o2 activated again.

I hooked up a wideband and went for a ride. Idle actually stays nice and close to stoich, but the rest of the map is all over the place. Cruising is very lean.
If you do it will undo his tune. That's why the sensors need to be deactivated.
 

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Discussion Starter #10
If you do it will undo his tune. That's why the sensors need to be deactivated.
That's the purpose of closed loop fuel injection though. The tune is only "right" on the day it is written. Any changes in temperature, humidity, barometric pressure, and elevation need to be accounted for with o2 feedback.

Locking in open loop is a very primitive way of tuning and has been obsolete in the car world for ages, I would hope motorcycle tuning is past that.
 

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Mine is currently disabled with a flash from Bauce Racing. It ran fine for years, but now it wants to load up and foul plugs if you do a lot of idling and sitting in traffic, and I'm wondering if it's too rich since it can't trim out fuel.

Its not a HUGE problem, it goes through a set of plugs maybe once a year. It is annoying though. The last hiccup happened in the middle of a road trip 2000 miles from home. Nothing like your bike starting to run on 3 cylinders when you're on the other side of the country.

I have a wideband kit on the way so I can see what's happening.
that is a problem. I raced 2yrs on the same set of plugs. Why does any shadetree think its 1950 and changes sparkplugs to "tune" it up? Modern plugs are good for 10s of thousands of miles.
 

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That's the purpose of closed loop fuel injection though. The tune is only "right" on the day it is written. Any changes in temperature, humidity, barometric pressure, and elevation need to be accounted for with o2 feedback.

Locking in open loop is a very primitive way of tuning and has been obsolete in the car world for ages, I would hope motorcycle tuning is past that.
That's just how it works. It will turn any changes back to the ultra lean stock condition. However, a piggyback system like the power commander uses a wideband O2 so it knows the exact afr. Narrowband sensors cannot do it. By using the wideband sensor you can tune the power commander map and the map will remain as you wish. I believe it is capable of doing the needed compensation adjustment as you ride .
 

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Discussion Starter #13
That's just how it works. It will turn any changes back to the ultra lean stock condition. However, a piggyback system like the power commander uses a wideband O2 so it knows the exact afr. Narrowband sensors cannot do it. By using the wideband sensor you can tune the power commander map and the map will remain as you wish. I believe it is capable of doing the needed compensation adjustment as you ride .
I'm having trouble finding out how this exact system works, but cars with narrow bands ignore the o2 feedback once the engine is under load. It shouldn't overwrite your tune, because that is the open loop area of the map. O2 feedback is only used for idle and light load, except for very late model vehicles that run widebands and full closed loop all the time.
 

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Discussion Starter #14
that is a problem. I raced 2yrs on the same set of plugs. Why does any shadetree think its 1950 and changes sparkplugs to "tune" it up? Modern plugs are good for 10s of thousands of miles.
I know its a problem, which is why I'm trying to diagnose it.

I hooked up a wideband and its actually pretty lean under light load and at idle. I've sent the ecu off to be re-tuned, hopefully it's closer this time.
 

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Obd2 is wideband. Watch the live data. Is the stock heated sensor wide? I doubt it.
 

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Discussion Starter #16
Obd2 is wideband. Watch the live data. Is the stock heated sensor wide? I doubt it.
Nope, only the very latest cars use widebands. Think 2015+. My 2016 Subaru is the first car I've owned with a factory wideband sensor.

The earliest adopters were VW back in the early 00's, they certainly weren't using them back in 1996 when OBDII became standard.

The stock R6 o2 sensor is not a wideband as it only has 4 wires. All my wideband sensors have 6 wires. Pretty much everyone uses the Bosch LSU 4.9.
 

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Obd1 non heated are 0 and 1 volts only. Obd2 is 0 through 1 volt with infinite scale. True it is not a full lambda sensor in that 8 to 16 afr isn't detectable, but it is functional on both sides of 14 with accuracy.
 

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Discussion Starter #18
Good luck trying to get anything useful out of those old narrow bands. They act more like a switch than a linear wideband, with a big voltage jump as it crosses stoich.

The only thing they tell you is which side you're on. There is no accuracy outside of that.

I've tuned obdI cars and earlier obdII cars and their o2 sensors act the same. The main difference is that obdII cars have a downstream sensor to monitor cat efficiency, which is what I have a hunch the R6 is doing. You can't get any useful information from probing the exhaust gas post cat, especially with air injection.
 

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car guys :rolleyes: You realize your bike makes peak torque at 11,000 rpms? Trying to fiddle with pedestrian rpm below is silly... and why the R6 is such a terrible street bike.
I managed to get 108 mph out of a bone stock 2014 R6 in the 1/8th mile. Thats 0 to 108 in 6.8 seconds. Im 200 in street clothes. No gay assed straps or swing arms or lowering it.
The sensor does bupkiss above idle.
 

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Discussion Starter #20
car guys :rolleyes: You realize your bike makes peak torque at 11,000 rpms? Trying to fiddle with pedestrian rpm below is silly... and why the R6 is such a terrible street bike.
I managed to get 108 mph out of a bone stock 2014 R6 in the 1/8th mile. Thats 0 to 108 in 6.8 seconds. Im 200 in street clothes. No gay assed straps or swing arms or lowering it.
The sensor does bupkiss above idle.
Congrats?

I want a bike that doesn't run like shit at idle. Sue me.
 
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