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Cupcake_mike
Posted on Saturday, October 22, 2016 - 08:55 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

On my uly at about 80 mph in 5th gear (4k rpm) if it is above 70 degrees I will get a cel pretty regularly (probably 40% of the time), with it going into what seems like skip spark (maybe 5% of that time). This has been happening for the last 7k miles (3 months or so). The only codes stored in the ECM are O2 low/no voltage). The CEL goes away once i drop below 2k rpm. Where it is happening in the rev range seems to indicate that it is switching between open and closed loop, thus bad O2 sensor, giving me the CEL.

When this first happened I replaced the O2 sensor with the bosch 12014 replacement and it stopped for a thousand miles or so, then it started again. I did check continuity of the stock harness when I replaced the O2 sensor.

But, here is where it gets interesting, if the temp is below 70 or I am in 4th gear pulling 4K (approx 70 mph) I get no CEL or ECM codes.

It seems like if I stop and wiggle the wire coming out of the O2 sensor the symptoms will go away but its probably just a coincidence (as I said it doesnt happen all the time).

My bike has about 50K on it and the fuel mileage hasn't really changed through all this.

So, what do you guys think? Just another bad O2 sensor? Its weird to me that it would happen in 4th but not in 5th in the same rev range and the whole temp thing (since 70 is so mild).

(Message edited by cupcake_mike on October 22, 2016)
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Sagehawk
Posted on Saturday, October 22, 2016 - 10:53 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Are you able to datalog all of this and it repeats ? And what is normal afv?
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Cupcake_mike
Posted on Saturday, October 22, 2016 - 11:33 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I dont know how to datalog...I read the codes with my bluetooth adapter and ecmdroid app on my phone, in my garage.

I could tell you my AFV at idle, but I doubt thats what you are asking about...
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Cupcake_mike
Posted on Sunday, October 23, 2016 - 09:04 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Afv is 103.9% and doesn't change revving to 5k in the shop, although i believe the engine has to get to a certain temp before this even comes into play, correct? I am not running it long stationary like this...the code its throwing is actually "rear O2 inactive"

(Message edited by cupcake_mike on October 24, 2016)
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Steveford
Posted on Sunday, October 23, 2016 - 12:31 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Time for another sensor.
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Ratbuell
Posted on Sunday, October 23, 2016 - 01:29 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Yep.

The EFI uses the O2 to "tune" the mix at all times. I run an a/f meter gauge on all my turbocharged cars to make sure I don't hole a piston under 35psi of boost pressure. At cruise...that gauge (a ring of LED's from red to orange to green) is a constant sweeping light show, as the computer adjusts the fuel a couple dozen times a second. The lights only go "steady state" at WFO (when I make sure I'm well in the green), when the computer simply sends an "open" command to the injectors until I lift off the pedal.

Buell EFI is the same. And at different RPM's, the sensor "sees" different gases in the exhaust and sends different readings to the computer. Sounds like either your sensor is out of range at the 5th gear load / throttle combination, where it's not out of range in 4th because of the differing load and throttle parameters.

Either that or you got something (anything) chemical on the sensor nipple during installation. Brakleen, RTV, fingerprints, ANY of that will cause the sensor to go wonky. Treat it like a light bulb - do NOT touch it at all. Put any thread sealant on the sensor threads, not on the header threads (so you don't run the risk of tapping the sensor against the sealant on the way in).
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Cupcake_mike
Posted on Sunday, October 23, 2016 - 07:44 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Damn, I wish my hands were smaller
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