All 650Rs Cbr650r after market exhaust o2 sensor problem

[matt_650r]

Hi everyone, I have encountered a problem while fitting a black widow system to my 2024 cbr650r. I’ve just noticed that the bike has 2 sensors going into the exhaust. The o2 sensor on the right side of the bike that goes into the pipe but there’s another sensor on the left side going into the back box. I have traced the wire to where it connect just above the shift linkage. The black widow system only has a hole for 1 sensor and I did check with them before buying that it would fit this model year. Should i just replace the stock exhaust and return the black widow system or could I just unplug the 2nd sensor or would that throw a code and bring the engine management light on?

 

[Redrocket]

AFAIK the 2024 model meets Euro5+. It is my understanding that the + bit means that there is another sensor after the cat which is there to measure emissions after the exhaust gasses have passed through the cat so that it's efficiency can be measured over time. Until now there has been no requirement for bike manufacturers to test how long the efficiency of the cat is maintained.
So, with an aftermarket exhaust and assuming you have a new EuroV+ compliant model I would have thought that a pre-2024 and 2024> model is not the same in this regard, unless anyone here knows better (though the 2024 is only just available). Maybe the aftermarket exhaust supiers haven't had enough time yet....

 

[matt_650r]

ah ok, annoying as I did contact them specifically to ask if the exhaust would fit the new model and they said it would all fit no issues. What would be the consequence of removing the secondary sensor? Would it have any affect on fueling or throw an engine management light

 

[matt_650r]

There are o2 eliminator kits that come with a blanking cap to plug into the sensor connector to stop water or dirt getting in, can pick them up very cheap on eBay. Not sure what affect it would have removing it though

 

[miweber929]

There are o2 eliminator kits that come with a blanking cap to plug into the sensor connector to stop water or dirt getting in, can pick them up very cheap on eBay. Not sure what affect it would have removing it though

You’re just tricking the bike into thinking it has working o2 sensors which mostly monitor the gases going into and out of the cat so with that removed the sensors aren’t doing much. You should be just fine.

You could also have a bung fitted to the pipe to mount the second sensor, not hard and fairly inexpensive.

The pipe fit the bike so Black Widow wasn’t exactly wrong with saying it would fit, and many pipe makers don’t provide any bungs for sensors so in their eyes it’s probably a fitting pipe. I’d let them know, however.

 

[matt_650r]

You’re just tricking the bike into thinking it has working o2 sensors which mostly monitor the gases going into and out of the cat so with that removed the sensors aren’t doing much. You should be just fine.

You could also have a bung fitted to the pipe to mount the second sensor, not hard and fairly inexpensive.

The pipe fit the bike so Black Widow wasn’t exactly wrong with saying it would fit, and many pipe makers don’t provide any bungs for sensors so in their eyes it’s probably a fitting pipe. I’d let them know, however.

Thanks for the help mate, if the second sensor is to monitor the efficiency of the cat but it is fitted to an exhaust system that has no cat would it not throw and engine light ?
Fitting the sensor might be the only option as I can’t find anywhere that sells a cap for the connector.

 

[miweber929]

Thanks for the help mate, if the second sensor is to monitor the efficiency of the cat but it is fitted to an exhaust system that has no cat would it not throw and engine light ?
Fitting the sensor might be the only option as I can’t find anywhere that sells a cap for the connector.

It might, an engine tuner or shop should be able to tell you for sure. I don’t know how sensitive they are or even what value it is looking for so I would agree a sensor bypass plug might be the best option.

 

[Redrocket]

I don't know about these bikes in particular but it is my understanding, based on experience of remapping other bikes over the years, that whilst cat removal has no impact on fault codes, disconnecting an O2 sensor will unless the ECU has been remapped to ignore the signal from the O2 sensor (ie it runs open loop all the time) or a resistor with a fixed rating is substituted for the sensor, fooling the ECU into thinking it's getting a valid signal from the sensor (the resistor has to be within the parameters set by the ECU).
The purpose of the O2 sensor is to analyse the emissions for unburnt fuel content with the purpose of dragging the fuel mixture back to stoichmetric AFR ie the fuelling is such that complete combustion occurs, thereby minimising the emission of CO. Complete combustion is not the same as optimum fuelling, which is a little richer than stoichmetric. Given the purpose of the O2 sensor I would have thought that not having one working within expected parameters and not adjusting for this as explained above would trigger an ECU fault. I don't know about O2 sensors after the cat but I would think the same would apply, in which case a fixed value resistor would probably be needed.
My take on it; others might well know better.

 

[matt_650r]

I don't know about these bikes in particular but it is my understanding, based on experience of remapping other bikes over the years, that whilst cat removal has no impact on fault codes, disconnecting an O2 sensor will unless the ECU has been remapped to ignore the signal from the O2 sensor (ie it runs open loop all the time) or a resistor with a fixed rating is substituted for the sensor, fooling the ECU into thinking it's getting a valid signal from the sensor (the resistor has to be within the parameters set by the ECU).
The purpose of the O2 sensor is to analyse the emissions for unburnt fuel content with the purpose of dragging the fuel mixture back to stoichmetric AFR ie the fuelling is such that complete combustion occurs, thereby minimising the emission of CO. Complete combustion is not the same as optimum fuelling, which is a little richer than stoichmetric. Given the purpose of the O2 sensor I would have thought that not having one working within expected parameters and not adjusting for this as explained above would trigger an ECU fault. I don't know about O2 sensors after the cat but I would think the same would apply, in which case a fixed value resistor would probably be needed.
My take on it; others might well know better.

Thanks for the info, as of now I can’t find a ‘dummy’ plug for the sensor that is specified to fit this bike and as you said the resistor in it would have to be specific to mimic what the ecu wants to see. And I have been in touch with a reputable tuning company who said that removing the cat/fitting a new catless system but fitting the 2nd sensor would be fine and not throw an engine light.
Will update with what I end up doing

 

[Patryk93]

Firetong already has a dual-sensor exhaust on offer for the 2024. The question is, without a catalytic converter, won't there be a check engine light ?

Firetong Dual Sensor

 

[Brammers]

Search for Lambda sensor eliminator or O2 delete kit. They're easy enough to find. It's just two resistors after all.

J

 

[Redrocket]

No engine light if cat is removed because the cat itself has no sensor to upset the ECU. It is the O2 sensors that, if eliminated, signal a fault. Substituting a fixed resistor that is within expected range prevents this. Cat removal has nothing to do with it.

 

[matt_650r]

No engine light if cat is removed because the cat itself has no sensor to upset the ECU. It is the O2 sensors that, if eliminated, signal a fault. Substituting a fixed resistor that is within expected range prevents this. Cat removal has nothing to do with it.

But if the 2nd sensors specific purpose is to monitor the cat then would it not trigger an engine light if there’s no cat for it to monitor but the sensor is still fitted

 

[matt_650r]

Search for Lambda sensor eliminator or O2 delete kit. They're easy enough to find. It's just two resistors after all.

J

Can’t find one for the 650r

 

[matt_650r]

Firetong already has a dual-sensor exhaust on offer for the 2024. The question is, without a catalytic converter, won't there be a check engine light ?

Firetong Dual Sensor

Never heard of firetong, will have a look at there systems thanks

 

[Redrocket]

But if the 2nd sensors specific purpose is to monitor the cat then would it not trigger an engine light if there’s no cat for it to monitor but the sensor is still fitted

I would have thought that the ECU would compare the reading of the O2 sensor after the cat with that of the one before the cat to establish whether it was different. If it's the same (which it would be without the cat) then the cat cannot be working and a fault would show. That is why a fixed resistor within the expected but different ranges of each O2 sensor is needed. I might have it all wrong, but that appears to me to be logical

 

[matt_650r]

I would have thought that the ECU would compare the reading of the O2 sensor after the cat with that of the one before the cat to establish whether it was different. If it's the same (which it would be without the cat) then the cat cannot be working and a fault would show. That is why a fixed resistor within the expected but different ranges of each O2 sensor is needed. I might have it all wrong, but that appears to me to be logical

That’s what I’m saying mate, seems logical to me but the tuning company I’ve spoken too says it won’t trigger an engine lights and so has all of the exhaust companies I’ve asked haha so someone will have to be the Guinea pig and try it out and find out

 

[Redrocket]

OK; I'll not argue; what they say doesn't make sense to me but I probably misunderstand what Euro V+ measures. I guess that's the problem with modding a new model - someone has to be a pioneer. Good luck!

 

[FLC]

IXIL just released their exhaust for 2024 - no cat, 2x O2 sensors. I personally like this one quite a lot but will wait to see what Akra puts out before deciding what to get.

IXIL FULL SYSTEM RC RACE XTREM CARBON exhaust pipe for HONDA CB 650 R 2024 (RH16)

FULL SYSTEM - RACE XTREM CARBON - HONDA CB 650 R 2024 (RH16)

ixil.com

 

[jamo]

IXIL just released their exhaust for 2024 - no cat, 2x O2 sensors. I personally like this one quite a lot but will wait to see with Akra puts out before deciding what to get.

IXIL FULL SYSTEM RC RACE XTREM CARBON exhaust pipe for HONDA CB 650 R 2024 (RH16)

FULL SYSTEM - RACE XTREM CARBON - HONDA CB 650 R 2024 (RH16)

ixil.com

Hi mate, looking at getting this, do you know if they ship in UK? you cant just buy off their website it seems. thanks.