Poor Running at Cruise Speeds - Possible O2 sensor?

[shabangles]

I have an 07 Uly and have recently had a horrible misfire at cruising speeds. The bike will begin to stumble and loose speed until I increase throttle, then it will come back to life and run fine as long as I am accelerating. I have connected the bike to ECMSPY and am finding that my AFV keeps setting itself to 130-140% almost immediately after I start riding. I have also noticed that if I allow the bike to idle and watch the EGO correction rapidly climb to 200% with almost no reaction from the o2 sensor. I can rev the bike and seem to get decent o2 sensor readings, but it drops back down to 0 as soon as the bike comes to idle. I also datalogged the bike yesterday and found that it wanted some extremely rich values at idle and cruise speeds, which does not seem correct to me.

This whole problem started when I had the rear rocker box gasket replaced under warranty about a month ago. The dealership also replaced a fuel line since they say it was damaged on removal. I picked the bike up and it seemed to run ok on the way home but started acting up the next day so I went back to the dealership. I had installed a Buell race kit a few weeks before any of these problems and the bike had been running great, but the dealership immediately blamed my "aftermarket" muffler for the problems. They finally agreed to check the bike out and ended up replacing the cam position sensor and rear plug wire, but they said it will never run right unless I pay them to dyno tune it.

I do not believe the problem is the race kit at all, so today I checked for intake leaks with some propane and carb cleaner, but did not find any. I then pulled the plugs and both looked rich, with the front being solid black and the rear having a slight amount of grey at the tip. I am suspecting that my o2 sensor is acting up after being coated with oil from the rocker box leak. Does this sound like an o2 sensor issue? The only other thing I can think of would be an exhaust leak, but I do not see or hear any evidence of that either.

Sorry for the novel, but I have been stumped for a month on this.
Thanks

 

[Stevenc150]

Welcome to the Forum. Have you done the breather re-route yet? It helps with lower RPM stumbling and the "coughing" at cruise speeds. It may not solve your problem, but it has a good possibility of at least helping: Breather Re-route w/Pics

 

[shabangles]

I did the reroute a few months ago and it did make the bike run a little bit smoother at cruise. After having someone look over my data logs we were able to determine that I had a short in the O2 sensor wire. I ran a new wire today and the bike seems to be running great.

 

[Stevenc150]

Good to hear. Care to expound on how you figured out your problem from the datalogs? Might help someone else in the future.

 

[shabangles]

After looking over the data logs we noticed that my O2 sensor was not showing a steady .49-.51 volts while it was warming up. I was told that it should hold a steady voltage until the sensor is warm and then it will begin to fluctuate. I disconnected the O2 pin from the ECM and was able to determine that the ECM was sending out the .49-.51 volts. I then disconnected the sensor from the other end of the harness and checked to see if I was getting the steady voltage there. I found that I was getting fluctuating voltage at the O2 sensor plug, so this led us to suspect a short. After running a new wire from the ECM to the O2 sensor and bypassing the factory harness we found that I showed the steady voltage while the bike was warming up. I have been running the bike this way for a few times and after data logging it several times my fuel map makes sense. I have changed the plugs to Irridiums and the bike smoothed out even more.

 

[Stevenc150]

Good to hear. [up]

 

[ches]

that sounds just like my problem do you have your own ecm cable