I wouldn't worry about crash bars and other such farkles. Most every bike has lots of mods.
Iirc, the ECU calculates or detects an O2 sensor problem based on the voltage being an unexpected value, not by actually measuring an open or a short. It could be your aftermarket exhaust causes the mixture to be so far off from nominal that the ECU interprets it to be a wiring failure. The error code may go away with the original exhaust re-installed.
Another possibility is something else is causing the mixture to be so far wrong that the exhaust stream is out of whack. Does the engine run normally with the aftermarket exhaust installed? Have you noticed a difference in fuel economy?
I installed all my farkles, including the aftermarket exhaust at about 1000 miles. Since then, I haven't had an O2 fault (or anything else) for probably the better portion of over 3000 miles.
To answer about mileage, I get anywhere from 50-60 MPG. On average I get 55 MPG. With my stock exhaust it was more like 53 MPG. But honestly, it all varied based upon traffic and such during the week. Otherwise, the bike runs great...with either configuration..even with the fault code on.
For those viewing this thread for the first time, your profile states a 2017 650 ABS Versys.
I assume you used the testing method in the service manual?
In 3-71 to 3-73, is testing methods to check continuity to the sensor and voltage measurements. You will need a good digital meter that can read 2 decimal places, as the voltage is between 0.2 VDC or normal heated VDC @ 0.5 VDC.
A common problem is the ECU frame grounds, FYI believe it or Not, the negative VDC input is not connected to the battery on many of the multiple grounds of the ECU, instead they use frame grounds, many are 18 or 20 gauge wire. Some of this is to eliminate electrical noise .
I see you already have a T Bob , some of the manual testing requires removing the harness from the ECU, if you look at the ECU Flash thread, steve has a video of how to remove the ECU , I also posted some pictures of how to relive pressure holding the ECU in place. From reading the manual, you have one of 3 possibilities; open wiring;poor / corroded ECU ground;shorted or open oxygen senor . If the bike is under warranty, I would take it in once you have restored the exhaust to original.
If it is covered, find out exactly what they found. A word of warning, if the after market exhaust caused the problem, you re-install the exhaust and your sensor goes poof again, expect suspicion and no further warranty. Some settings will remain in the ECU. What I would suggest is to try clearing the fault codes after the exhaust change , if it is still at fault take it in.
They will likely know the code has been cleared however you seem to be a technical guy, and I wouldn't hesitate to say you thought it was a loose connection, the dielectric grease on the connector will testify to that.
If it is out of warranty, it should be fairly simple to prove , by following 3-71 in the manual. feel free to post within this thread. I can move the posts later.
Thank you, I'd appreciate it moving to the proper location eventually.
I do ride in the rain alot. But on the particular day it happened, it wasn't raining, although, I think it was raining quite extensively the day before. So wherever these "electronic grounds" are located may have something to do with it. The service manual I have is a for the 2014 and earlier. Hopefully it's close enough to the 2017. I am interested in finding these grounds but ALSO the "Water-Proof Joint" which seems peculiar to me as well!
But I'd figure that if I had a bad ground to the ECU, wouldn't the ECU not turn on at all? Strange. But I DO intend trying to backprobe the ECU connector to the O2 connector to make sure the data wires have continuity. Wires pin 4 and 22...(from the 2014 manual)?? The one signal wire goes through that "water-proof joint."
When trying to clear the fault, I'm unsure as to how to do it. one service manual says something about holding in the clutch lever for 5 seconds..and grounding a wire? I looked under my seat and couldn't find this wire exactly.
According to federal law, headers and/or exhaust systems which remove, modify or defeat existing emissions controls (for instance, if your catalytic converter has been removed) will void your warranty. It is up to the dealership to make that determination, and burden of proof is on them (not that it makes any difference).
With that said... I'd be interested to see what happens in a state like California where cars and light trucks have a state mandated 8/80 emissions warranty. That probably won't help you, in either case.
So here's a caveat that I didn't fully explain. The 2015+ exhaust is all one piece (ergo, header, muffler, and "catalyst"), the 2014 and earlier is actually a two piece. What I've done was purchase a 2014 and earlier exhaust "header" and used the scorpion slip on portion (that's why I explained having a scorpion slip on in my sig). So is it really
an aftermarket exhaust?
This actually ended up being much cheaper and for the most part bolted all up just like it was a 2014. I then just needed to buy two exhaust gaskets to properly crush and seal. In addition, of all the aftermarket exhaust, I couldn't find full exhausts that included cross-over pipes nor ones that were as "compact" enough for things like ground clearance and aftermarket skid plates (another concern).
As for anyone else, thank you for the warm welcome to the forum!