I took the vance and hines pipes off my 2008 cvo so i could put the original pipes back on. The wire to the sensor kinda just flopped out and came with the pipes as i was removing them and i thought it just unplugged by itself., no big deal.

so now when i was gonna put the original pipes back on i located the wire to hook the sensor up and i notice it is "Plugged" with some sort of plug, so it was not connected in the first place.

so now i am wondering what i should do, since i have no idea what this plug thing is. anyone else come accross this? thanks in advance. (PS I bought the bike used and the previous owner has no idea.) ( I also seen i wring diagram that shows only the front oxygen sensor. And Even stranger is i have another bike (exact same year and model that has different pipes and there are no sensors at all, and that bike runs great)

 

I am assuming you purchased the bike used, with the Vance & Hines pipes.... correct?

Does it currently have a piggy back tuning device attached to the ECM?

Those are probably O2 sensor eliminators, that plug into the O2 sensor wires so that the ECM doesn't set a diagnostic code because it doesn't "see" the O2 sensors...

Something like these...
https://www.ebay.com/itm/193961641839

People use them when they don't do a proper tune that shuts off the O2 sensors, and doesn't use the O2 sensors in their new "tune"... They either go with some sort of piggy back fuel enricher, or God knows what else. I have never been a fan of doing that, so I am purposely ignorant of the many ways people like to "fool" the ECM, rather than do a proper tune.

If the bike is running well, and you are just switching one high flow exhaust for another, you could keep them on, not use the O2 sensors, and see if the bike runs well...

IMHO, if you decide to keep the bike as is and not use your O2 sensors, I would remove them from the pipes and put O2 sensor bung plugs in the head pipe in their place.... it's just a cleaner look, better installation, and you can keep the O2 sensors safe for possible future use.

However, I suggest you get the bike tuned properly for your mods.. either with or without using the O2 sensors. Then you won't need those plugs to "fool" the ECM.

If you chose to do a proper tune, you will need to get a tuner and reflash your ECM with a tune for your mods that uses the O2 sensors, or doesn't use the O2 sensor feedback and turns off the O2 sensors in the tune. That could all be handled by a good, experienced dyno tuner Then you could throw those plugs in the trash, where again, IMHO, they belong....

 

As hattitude says.... Some one obviously tuned the bike to run in open loop.. Changing the pipes could alter the way the bike runs because the tune is not set up for the new pipes. I would look for some type of tuner tucked away under the seat or bring it to a local Indy... It might just even have XIED's to fool the ECM...

 

yes, i bought the bike used. the front sensor was attached, and the rear had the O2 sensor eliminator. i drove the bike once and it ran very well like this, witht the vance and hines pipes pictured above, which had baffles in them. Ssomeone wanted those pipe more than i did, so i took them off and now i am putting the original pipes back on.

since i dont know if this bike was ever "tuned" at all, i will see how it runs with the eleiminator in the rear pipe. if it doent run good i guess i can remove the eliminator and plug in the o2 sensor back in like it was orriginally.

someone asked me to find this particular bike since they are in kuwait. afteri got it they changed their mind so i am stuck with it for now. once i get the original exhaust back on and get it running right and remove that hideous seat, i will put it up for sale.

i never had a bike with o2 sensors, so all of this is new to me. i am an old man.

 

Nice bike though.. Should sell rather well.. CVO Softail Springer... Nice..

 

I have no idea what you have going on with your "tune". I would NEED to have it investigated and fixed if it were my bike.

I have never heard of a tune that runs front cylinder in closed loop and the rear cylinder in open loop. Also, I have never heard of an enriching device that only wants you to remove one of the two O2 sensors.... What you have makes absolutely no sense to me...

If someone understands how your bike was "tuned" I sure hope they post up.... because I am at a complete loss...

 

If it runs good and you're going to sell it I wouldn't even worry about changing anything.. Ride it and enjoy it while you got it and then just unload it.. Why put money into something ain't going to keep anyways...?

 

its not "my" tune. but i am curious about it. someeone before me did some half assed stuff i guess.

BUT, the bike was running good.

I have no idea why they did this. i will put the original exhaust back on and see what happens, and go from there.

i asked the guy that sold it to me if the pipes had baffles when i first saw it. he said he didnt know. he was clueless. i bent down and looked and saw the baffles. he said he bought the bike to impress the ladies, but now he was too old and wanted rid of it. he probably never rode it more that 5 miles at a time.

as i said, i drove it once, about 15 miles and it drove great, i would never have know something was amiss had i not taken the pipes off.

from what i gather, to properly tune on eof these can be quite expensive.

i would "guess" it was never "tuned". someone probably changed the pipes and disconnected the rear o2 sensor and said thats good to go.

all i am probably doing is putting it back to the way it left the factory, and that good enough for me, since i am selling this one. the original exhaust i have looks like it is brand new, and the seat i have for it was never used.

the other one i have has the vance and hines propipe, and it has a usb plug under the seat, and NO O2 sensors whatsoever and it runs like a scalded ape.

the bike only has 14,800 miles, so if anyone want one, heres your chance, i just want to break even.

 

I didn't mean to insinuate that you tuned it. I should have said, "The bike's tune"

That bike's tune, if it was actually tuned, is certainly unconventional by any standards I know... and the fact that it ran great if they just pulled one O2 sensor and called it good, is mystifying to me...

Just FYI... There is really nothing that special about that bike in terms of what it takes to tune it.. It's just a Twin Cam with some mods... But tuning any engine can get expensive on any bike, depending on how you choose to go about it...

I missed that you were going to sell it... Putting it back to OEM for the sale is probably the best course of action...

As for a bike with no O2 sensors running like a "scalded ape" that is not the least bit surprising to me. Many very high performance bikes use an all open loop tune, and run very well.

All the EFI Harley's before 2007 had no O2 sensor feedback, ran all open loop tunes, and ran very well...

I have an '03 Heritage with a 95" big bore kit with headwork. It is an all open tune EFI bike... and it runs really, really well... I think it would qualify for "scalded ape" status..

I also have a '16 Bagger with a 124" crate engine @ 135HP & 151TQ, that runs the standard partial open loop, partial closed loop tune with O2 sensors.... It runs really, really well too....

On a Street driven bike, either tune strategy can work really well if done properly....

Good luck with the repairs and the sale... Keep us posted .......

 

I put the original exhaust back on, left the rear o2 sensor disconnected. took it for a short ride and although very quiet, the bike ran fine, no issues, and no faults light came on. there is zero point in me getting a tune for the bike now. the next owner will no doubt remove the original pipes and he can tune it up until his heart is content.

thanks for the education on the o2 sensors, as i said, its the first time i ever messed with them.