Closed Loop and O2 Sensor Question

[yotogi]

I was cleaning my bike last weekend and while doing so, I noticed that one of the electrical system plugs is not properly plugged in. I hook it back up not really thinking about how or why it had wriggled loose. Then I was reading in another post where this plug was identified as the wires that run to the O2 sensor.

Now, I have an 06 S2R1K. I would have thought that a fault from the O2 sensor would trip the check engine light. Mine hasn't been coming on. Since I reattached the sensor I now am getting all of the really wonderful low RPM issues that the rest of the community has been reporting. The bike has definitely taken a step backward, but I am not sure that I really want to run no O2 sensor. I suspect that I am going to be getting a FatDuc to address the issue but should I leave the O2 sensor hooked up or go back to the way I rode it for 6 months?

I suspect that the bike was running very rich when I had the sensor unplugged, I have to wonder if it is bad enough to deal with the low RPM crap or if I shouldn't just unplug it again.

Advice?

[teddy037.2]

you could take it to the dealer and have them check the trim on your ECU to see...

how do your spark plugs look?

or you could unplug it and just let it be, since it seemed happier that way 

[yotogi]

you could take it to the dealer and have them check the trim on your ECU to see...

how do your spark plugs look?

or you could unplug it and just let it be, since it seemed happier that way 

The Streetfighter unveiling is this weekend so I was planning on being at the dealership anyway. I will have them check it. Thanks for the advice.

[teddy037.2]

mmmm, the streetfighter...


I always said the 1098'd be better lookin' nekkid 

[Tigermeat]

Any exhaust or airbox mods?  Any other reason the O2 sensor would be disconnected?

[Howie]

Early SR1000s would not set the check engine light if the O₂   sensor was disconnected and the memory cleared.  How well the bikes ran with the O₂ disconnected seemed to be a crapshoot.  If yours runs and starts well with it disconnected, I would leave it that way and save my money.  If you want to run the O₂, many of the running issues were due to poor dealer set up.  Cam timing, valve clearance  TPS and throttle synch should be checked first, then add the Fat Duc.

[yotogi]

Thanks for all the tips Howie!

As to mods, I have a mid-pipe, so no udder. Cans and airbox are stock. I know the mid-pipe could cause the lean condition to be worse. The real question I now have is:

Is there anything else that happens when the O2 sensor is disconnected? It really feels like the bike is running really different when in open loop mode. Above 4,500 RPM the bike seems so much better. I could be crazy and imagining all of it but...

The bike was running really rich in closed loop. Hard to say if open loop was effected, can't really smell the exhaust while moving. Considering how fantastic the bike is when run up, I don't think I want to just leave it unplugged.

[Howie]

As I remember, some ran rich, some lean, some really well, a little like winning the lotto.  Some claim you can trim CO with the VDSTS (Technoresearch) software, some say you can not.  One of the most knowledgeable people on this board in this area is brad black.

[Tigermeat]

The late-model ducs are notoriously lean in the closed loop and your udder has fallen off.  FatDuc puts you in control of the situation.  Check some of the many previous threads and you'll find everybody that runs FatDuc (including me) is pretty satisfied with the results.  It's a relatively cheap mod at about $90 to yor door.  Make changes every 4-5 rides until you find the sweet-spot.  It'll tame your throttle down, widen your power range and cut the pops/stumbles.  Contrary to all I've read it actually increased my fuel mileage slightly.  Dunno about that one except my engine runs better = efficient?

[yotogi]

Thanks for the reply Tigermeat! I am still waiting for some more info about what happens during the open loop portion of operation with the O2 sensor unplugged. I am pretty sure that a FatDuc is on the purchase list, I just can't get over how much better the bike runs at higher RPMs with the sensor plugged back in.

[ProTeal55]

I just can't get over how much better the bike runs at higher RPMs with the sensor plugged back in.

I hear ya..
I ran my 07 S2R1K around for awhile with the O2 un-plugged and then one day for the hell of it plugged it back in and hit the tollway. It was like I had picked up 25HP or something. The FatDuc is the best way to go without spending a boatload of cash..

[He Man]

the O2 sensor defintely gives you more power, youre not wasting unburnt fuel that could be robbing HP, however since both cylinders feed off 1 sensor sometimes the amount of fuel in each cylinder varies to the point where you're bike will not be smooth.