Heated 4-Wire NBo2 Vs Stock Single Wire Unheated Sensor

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mmcn49

Well-known member
Joined
Jan 28, 2010
Messages
299
Location
Small Island in Puget Sound, WA
We've had a couple dry days here in the Northwest so naturally went riding. Had a nice run on one of the Buell's yesterday, but a different story on the other one today. Less than a mile down the road the engine started running rough and the Check Engine Light came on. Nursed it home and pulled the code with ECMSpy, (failed o2 sensor).

Not a big job to replace but a pain. Thinking I might put a heated 4-wire in.

Has anybody installed one?
Did the engine run any smoother?
Which brand and model would you recommend?

Looking forward to all comments and suggestions.

Thank you.
 
A heated O2 has nothing to do with "running smoother". It simply warms the sensor for faster transition to CL operation, simply for emissions purposes. Not even close to necessary on a motorcycle like your Buell.

Getting an O2 code does not mean to replace the O2. It simply says the ECM isn't seeing the signal it expects from the O2. Use the ECMSpy you used to get the code to also diagnose whether you need to replace it or not. Check running O2 voltages to see whether its a lazy, O2, wiring issue, or ECM fault. Sure, swap it a new one and see what happens, maybe you get really lucky:)

If you decide to throw money in the direction of random O2 sensors, you might as well get a WB kit and use it to tune the bike to "run smoother". Win!
 
Code 13: Sensor Always Rich, or Sensor Always Lean, or Sensor Inactive.
Did not look at the High Low Voltage switch rate in spy.
Sensor wire and connector look OK.
ECM connectors look OK.
Bike has 44K.
Don't know the issue for sure but its 13-16 Bucks for a single wire sensor and a couple hours to replace.
 
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At least look at the sensor voltage on ECMSpy to see if it has some. You'll get a code 13 if you have a pinched wire (a new sensor won't fix that). A new sensor also won't fix it if the bike really is always rich (clogged filter) or always lean (intake seals).

If you want to replace it anyway: Hang the rear tire slightly off the ground with a tie down from the pillion peg brackets to an A-frame ladder, pull off the seat, the rear shock, and the fan. A 7/8" crowsfoot on a 4" wobbly extension makes the O2 removal easy. It should take 2 hours if you spend an hour and a half doing something else:)
Good luck and post what you find
 
Thanks Cooter, you've jogged my memory. Did a few things to the bike over the past month or so including grip heaters. One of the other things I did may have have something to do with the issue the issue. So as not to embarrass myself prematurely I'll check things out tomorrow and get back to you.
 
OK so here we go: Pulled the airbox top off to clean and oil the K&N filter. Pulled the airbox bottom off to access a good ground point for the grip heaters negative wire. Air intake was open for a couple weeks while I did other things.

To prevent debris from falling into the intake I wadded up a couple paper towels, (they were small) usually use a rag. When I buttoned up I pulled out one paper towel, forgot about and didn't notice the second..

The bike runs great now, plenty of air, (funny how that works). Spied the bike after getting back from a test run. Oxygen sensor voltage fluctuations only went from 0.49 to 0.50 Volts. From ECM-Config in ECMSpy sensor voltages are set at 0.41 lean, 0.52 midpoint and 0.61 high. Think these were recommended by Xopti.

The sensor has a few miles on it but the bike runs too good for it to be getting tired. Your thoughts as to the small voltage changes, (.49 to .50 then back to .49).
 
To prevent debris from falling into the intake I wadded up a couple paper towels, (they were small) usually use a rag. When I buttoned up I pulled out one paper towel, forgot about and didn't notice the second..
Are you saying you rode the bike with a paper towel stuffed into the intake horn?!? And it luckily didn't get sucked through the TB into the engine??? One lucky boy you are! Do yourself a favor and use a rubber nitrile glover stretched over the rubber velocity stack from now on and preferably one that is a stand out color please!

The bike runs great now, plenty of air, (funny how that works). Spied the bike after getting back from a test run. Oxygen sensor voltage fluctuations only went from 0.49 to 0.50 Volts. From ECM-Config in ECMSpy sensor voltages are set at 0.41 lean, 0.52 midpoint and 0.61 high. Think these were recommended by Xopti.

The sensor has a few miles on it but the bike runs too good for it to be getting tired. Your thoughts as to the small voltage changes, (.49 to .50 then back to .49).

Modding the values for the O2 sensor never produced the desired results from when I researched it BITD, the theory is to modify closed loop. As Cooter mentioned a number of owners have modded up a multi wire NB sensor to come up to temp quicker I believe the goal was to work out the 12's stumble or off-idle hesitation before coming fully up to temp. Haven't been around the forum for a while BUT I still don't think anyone has come up with a way to have the ECM work off of a WB sensor, just pass the 0-5V data through for logging and tuning purposes (while O2 is disabled). Also never heard of a sensor dead (or stuck) right in the middle of its voltage range like that, if it was just stuck at .49 and didn't move I'd guess that was the last value transmitted to the ECM but apparently it is moving voltage by .01? What does it read with the bike not started but ECMSpy connected with live data?
 

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