Put a cheap slip on my NC, got a check engine light

[rippin209]

Ok so the title says most of it, I checked the MIL code and got 86

When the engine is cold sounds great runs great, after riding for awhile, 15-40 min engine light will come on and exhaust sounds poppy on deceleration other then that performance isn't noticeably better or worse.

After installing the slip I did the EFI reset steps (disconnect battery, turn on key, let sit at least 30 min, I left it over night, turn key back off, reconnect battery, start bike, let idle until the engine gets to operating temperature and shut off with kill switch them key)

I've been reading of others running with no CAT (I still have mine) and aftermarket exhaust or just the aftermarket exhaust without any problems or modifications mentioned, any ideas?

MIL code 86 is communication failure

 

[Rapturee]

Wow Ripp that is crazy. I have heard of others having issues like you mentioned and now are experiencing. When i removed my 30lb muffler and installed my new DanMoto pipe it has worked great since day 1 with no issues at all ever... Do you have a picture of your new slip-on?

Here is an old pic of it, many changes since but still enjoying the DanMoto!

 

[rippin209]

Wow Ripp that is crazy. I have heard of others having issues like you mentioned and now are experiencing. When i removed my 30lb muffler and installed my new DanMoto pipe it has worked great since day 1 with no issues at all ever... Do you have a picture of your new slip-on?

Here is an old pic of it, many changes since but still enjoying the DanMoto!
View attachment 39257

I just got home and took a pic

 

[rippin209]

Tomorrow after work I'll try putting the OEM exhaust on and see if it that fixes the engine light, oh yeah tomorrow's my first day back at work sense the accident in April

 

[TacomaJD]

Gotta be something else. There is not enough of a change in exhaust flow with just a slip on can installed, no matter the design or brand. Could probably run factory cat head pipe with NO exhaust can on it and not experience check engine light problems.

Also, there is no need to do any of the battery disconnecting and letting sit with key on for just installing a can, especially on these bikes. If there are little to no power gains to be had by aftermarket exhaust, air filter, and installing a tuner or getting ECU flashed, that means installing a simple slip on can is not going to change any parameters enough for anything to need to be reset.

Also I wouldn't waste time putting stock exhaust back on, I highly doubt it will change anything.

Maybe it's the o2 sensor failing, or something that happened as a result of leaving battery disconnected for so long with key on?

Is yours dct or manual model?

Here is a thread on something similar with a DCT model. Something about the clutch electronics screwing up from battery cable being undone for prolonged period of time.

86-1 code on 2015 Nc700x DCT


Sent from my SM-G930V using Tapatalk

 

[rippin209]

Gotta be something else. There is not enough of a change in exhaust flow with just a slip on can installed, no matter the design or brand. Could probably run factory cat head pipe with NO exhaust can on it and not experience check engine light problems.

Also, there is no need to do any of the battery disconnecting and letting sit with key on for just installing a can, especially on these bikes. If there are little to no power gains to be had by aftermarket exhaust, air filter, and installing a tuner or getting ECU flashed, that means installing a simple slip on can is not going to change any parameters enough for anything to need to be reset.

Also I wouldn't waste time putting stock exhaust back on, I highly doubt it will change anything.

Maybe it's the o2 sensor failing, or something that happened as a result of leaving battery disconnected for so long with key on?

Is yours dct or manual model?

Here is a thread on something similar with a DCT model. Something about the clutch electronics screwing up from battery cable being undone for prolonged period of time.

86-1 code on 2015 Nc700x DCT


Sent from my SM-G930V using Tapatalk

That's what I was thinking as well, I'll double check all the connections just in case but yes it's possible the 02 sensor is simply going bad (or has) I can't find my repair manual for the NC but I haven't come across any codes specific to the 02 sensor (that would or should have come up instead of 86) While researching this, I came across something saying the 02 sensor should last 60,000-80,000 miles, I'm just under 91,000 right now
My NC is a manual

 

[Rapturee]

Wow Aaron, you have 91k on yours...Yah Buddy!! I agree with TacoMan, i'd start with replacing the O2 sensor. That is a reputable slip-on and you should not be having that issue with simply installing it.

Seems coincidental to me that it happened at the same time, My money is on your O2 sensor. That's a good pic of your bike, the poor thing looks naked without a lower cover/Skid Plate haha. :{)

 

[rippin209]

Wow Aaron, you have 91k on yours...Yah Buddy!! I agree with TacoMan, i'd start with replacing the O2 sensor. That is a reputable slip-on and you should not be having that issue with simply installing it.

Seems coincidental to me that it happened at the same time, My money is on your O2 sensor. That's a good pic of your bike, the poor thing looks naked without a lower cover/Skid Plate haha. :{)

Nah it's a knock off I paid $20 or $30 bucks for from Wish, but I agree with Tacoma (heck look at yours, it's practically a straight pipe) knock off or not I think the NC should work with it, so something is off, the 02 sensor makes sense, we'll see one step at a time, I'll start with the stuff that doesn't cost money

 

[rippin209]

I was planning on painting and wrapping the exhaust (I've had the materials for 8 months) I've got to get this straightened out before I start changing anything else

I did mount a dual USB outlet with volt meter and it's own on/off switch but I rode 400 or 500 trouble free miles so I don't think that's it, I installed a ground bus the day before I ride towards Shuteye but I already had the check engine light come on before that. The first time the light came on was right after mounting the slip on so that makes the most sense, I'm just thrown off by the 86 code but I guess if the 02 is sending wonky signals that makes sense

 

[TacomaJD]

The o2 shouldn't be sending wonky signals, it simply won't be sending any signals at all. The o2 sensor helps the ecu determine the fuel/air ratio. If the o2 sensor has failed, it won't communicate with the ecu. This would explain the popping upon deceleration that is normally nonexistent.

Since it's not doing it all the time, it's possible the o2 sensor is intermittently failing to communicate since it seems to happen after it warms up. Sensors can definitely act like that. A few years ago, I had a little Saturn L200 with 2.2l Ecotec engine that was my little gas saver car. Crankshaft positioning sensor went out in it. To begin with, it was hard to crank sometimes (fuel injected car), and I would smell fuel...which is odd in something that is fuel injected. But I could usually mess with it and get it to crank. Then after a few weeks of that, it just stopped cranking all together no matter what I did, and still you could smell fuel really bad every time I'd turn it over. The crank sensor monitors the crankshaft's position so the ECU can control fuel injection and ignition correctly. Without knowledge of where the crank is, it was apparently dumping fuel in but ignition wasn't occurring at the correct time.

So sensors can start failing intermittently, then eventually just quit working. What you are experiencing, to me, sounds like o2 sensor. But I could be wrong and it wouldn't be the first time I've been wrong diagnosing over the interwebs. But I highly doubt it has anything to do with changing the exhaust.

Also, when is last time you changed spark plugs?

Sent from my SM-G930V using Tapatalk

 

[showkey]

Sent you a response on ADV rider.

Code 86 is communication error to the meter.
Past posts with this error have been traced back to low battery voltage or loose battery connections.
Since you modified the wiring at the same time as the exhaust that’s where I would look.
The other confirmed cause for 86 is a soft set electrical wire harness corrector ..........often after accessories install.

O2 sensor on the NC can be unplugged and it will not code. We have talked about this at length in prior posts. Several members have confirmed this.

A “soft set connector” is where the electrical corrector is place but not pushed completely to the locked position.

 

[davidc83]

Code 86 is a communication error to the dash.... the communication error could be a loose battery connection (even though it seems tight) or a loose display cable...(remove windshield, remove 3 screws, pull out about an inch, disconnect display cable, reconnect (all of this with the battery disconnected of course)...reconnect the display cable, reconnect display, reconnect windshield, reconnect battery terminals...see if it fixed the check engine light (did on mine this past May).

 

[rippin209]

Thanks for the advice, I'll start looking into the connections when I can, I'm back at work now so not as much free time, but I'll definitely hold off on buying a 02 sensor.

Last night I tried just unplugging the 02 sensor just to see if it makes a difference, the engine was cold when I started it and the idle was slightly fluctuating up and down, nothing crazy but it's usually solid, I reconnected the 02 sensor and the idle stayed solid as usual. Not sure if it would have changed if I let it run long enough to get to operating temp but I just shut it down.
Anyone willing to trying unplugging their 02 sensor and see how it behaves?

As I said earlier I'm definitely checking all the connections first but I'm still stuck on how this started as soon as I changed the exhaust, I had ridden hundreds of miles after doing the electrical without any check engine light

 

[TacomaJD]

Glad its not o2 sensor, maybe its a simple connection issue somewhere. I hate chasing electrical gremlins. Good luck!

Sent from my SM-G930V using Tapatalk

 

[rippin209]

Glad its not o2 sensor, maybe its a simple connection issue somewhere. I hate chasing electrical gremlins. Good luck!

Sent from my SM-G930V using Tapatalk

Right[emoji28] I don't now which one is worse buying overpriced sensors or chasing electrical problems.

I still don't know for sure it's not the 02 sensor AND something else, we'll see, has anyone actually tried running their NC with the 02 sensor disconnected?

 

[Rapturee]

Showkey to the rescue!! :{)

 

[showkey]

The O2 sensor on the NC is not a critical component.
It has one error code and the engine runs normally with that error code. ( as per the service manual).
The fuel injection on the NC is relatively simple but adequate system as compared to the modern automotive system that might have 3 to 6 O2 sensors in a 4 cylinder. BUT, As a comparison the NC FI system is light years ahead of the carburetor systems 10-20 years past.

There was another thread where we discussed missing or running rough engine , where the engine compression test, valve setting and 02 sensor function was in question. The 02 was unplugged on a normal running engine with no change. On the NC Unplugged or damaged O2 would certainly effect emissions and the catalyst would not be functioning at peak. The rider my not even be aware. On that note there would be no benefit in power, performance or MPG by defeating the O2 or catalyst on the NC. That has been discussed many times prior in several tuning posts.

The O2 on the NC has a main function of keeping the mixture at the catalyst in narrow range with an alternating slight rich and slight lean swing. That mixture swing is to allow the catalyst to store oxygen on the lean swing and burn excessive hydrocarbons on the rich swing. The 02 is “trimming” the mixture or checking mixture consistently.

O2 sensor on a more sophisticated bike or car system can and will do a lot more......like more ( trimming) mixture adjustments in real time for each cylinder ( long and short trim trim) , miss fire detection, catalyst monitors, engine performance, ..........so in those systems 02 will effect performance, MPG, failed emissions and have dozens of failure codes directly or directly associated with the 02 sensor.

 

[showkey]

Here is another data point. It’s from the VFR1200X forum but the symptoms are similar.
No code on the VFR if there was it was not mentioned.

Original post:

Honda). I was riding today in D mode at about 65 MPH. The bike was in 6th. All of a sudden the bike felt like there was just barely enough power for the gear...like a manual transmission...chug, chug, chug. It corrected itself. Then it did it again. I could not accelerate. It corrected itself again. I went on the back road and it did it three more times, but this time the engine died. It did seem like it was holding the gear too long after I got going again. I have not completed the DCT initialization procedure as recommended by another member, yet. Any ideas on what could be causing this?

OP posted a recent fix:



This is consistent with posts here and ADV rider that the battery voltage and the connections can cause some strange or unusual symptoms.

 

[indyDean]

After installing the slip I did the EFI reset steps (disconnect battery, turn on key, let sit at least 30 min, I left it over night, turn key back off, reconnect battery, start bike, let idle until the engine gets to operating temperature and shut off with kill switch them key)

... I'm definitely checking all the connections first but I'm still stuck on how this started as soon as I changed the exhaust, I had ridden hundreds of miles after doing the electrical without any check engine light

Just relateed to battery connection? ...or bumped something during the EFI reset steps?

 

[rippin209]

Code 86 is a communication error to the dash.... the communication error could be a loose battery connection (even though it seems tight) or a loose display cable...(remove windshield, remove 3 screws, pull out about an inch, disconnect display cable, reconnect (all of this with the battery disconnected of course)...reconnect the display cable, reconnect display, reconnect windshield, reconnect battery terminals...see if it fixed the check engine light (did on mine this past May).

This communication error is looking more and more like it. I installed a fuse block (around a year ago, 20,000 miles sense then) but I reused a 1 foot cable from a car that was being taken to the wrecking yard and thought that maybe there was a problem with the cable, so I just disconnected the whole cable and tightened both battery terminals (disconnecting negative first and reconnecting negative last) rode about a mile and a half no problem at all, ran great, 90 min later I go to ride home and half way there the engine light comes on, then my display flickers slightly, then the flickering got worse and when the display would cut out my engine would start to cut out (never shut off but ran terribly, luckily I was within a block or two of my house by then and was able to shut it off quickly.

Tonight when I get home I'll check the display plug and the fuses, hopefully it's that simple