Question About Eliminating Cat

[Lagunabzrd]

Hi All,

 

I just picked up a 24 TÉNÉRÉ 700 and was curious about doing a full exhaust. I was wondering if the bike will need to be tuned eliminating the catalytic converter or if the bike still runs the same. I’ve got a tuned 18 R1 and I did a full exhaust and the bike ran ok, but not the same, until I got it tuned. Was wondering if it might be the same situation, and if it’s even worth it power and sound wise or if just doing a slip on is good enough to get some better sound; I’m not expecting major power gains. 
 

Thanks,

Rob

[prowlnS10]

26 minutes ago, Lagunabzrd said:

Hi All,

 

I just picked up a 24 TÉNÉRÉ 700 and was curious about doing a full exhaust. I was wondering if the bike will need to be tuned eliminating the catalytic converter or if the bike still runs the same. I’ve got a tuned 18 R1 and I did a full exhaust and the bike ran ok, but not the same, until I got it tuned. Was wondering if it might be the same situation, and if it’s even worth it power and sound wise or if just doing a slip on is good enough to get some better sound; I’m not expecting major power gains. 
 

Thanks,

Rob

Yes, ecu flash is recommended for decat header & snorkel removal on the airbox.  I just had 2 Wheel DynoWorks flash mine.

[Rider 101]

Why do it at all?  

[Dougie]

Yeah it’ll never be a racing snake, but if you want to, I would go down the dimsport Rapidbike evo plug in so it’s self leaning and flexible. 

[Lagunabzrd]

7 hours ago, Rider 101 said:

Why do it at all?  

I’m a mechanic..I can’t leave anything alone. Honestly I just want the bike to sound good and to sound louder more than potential power gains and from what I’ve read online everyone says doing a slip-on only improves the sound on these bikes marginally. 

[Hollybrook]

The CamelADV exhausts sound great without removing the catalytic converter. I actually tried a set of headers and went back to the cat just for the sound. 

Edited July 5 by Hollybrook

[Rider 101]

I guess the sound thing is personal.

I have a slip-on and am happy with the note.

I believe removing the cat along with an ecu reflash gives a little more power and a reduction in the off-idle snatchiness of the throttle.

Mine will stay as it is.

[Totti]

Get your bike tuned. Just had mine (2019) done this spring and I only regret not doing it much earlier.

I have the Akrapovic slip on and LeoVince decat headers.

Bike runs so much better now.

The piggyback plugs are not even close compared to the ecu flash.

[SXXP]

On 7/3/2024 at 5:05 PM, prowlnS10 said:

Yes, ecu flash is recommended for decat header & snorkel removal on the airbox.  I just had 2 Wheel DynoWorks flash mine.

 

Yes, I understand the gains are optimized, BUT, will I be hurting the bike by not doing an ECU re-flash with a CAT-less header and freer flowing exhaust (+ snorkel removed)?

[prowlnS10]

20 hours ago, SXXP said:

 

Yes, I understand the gains are optimized, BUT, will I be hurting the bike by not doing an ECU re-flash with a CAT-less header and freer flowing exhaust (+ snorkel removed)?

A decat aftermarket header flows significantly more than the oem...without a flash or other method of correcting fueling it would be very lean under certain conditions, load & rpm...snorkel removal would increase air velocity & flow leaning out the mixture as well...I am not qualified to state if it would be harmful to your bike but the result of leaner mixtures is the motor & related components run hotter & more susceptible to pre-detonation...which can't be healthy for any modern motor that already is leaner than optimal, so would not do those 2 changes on my bike.  Here is some ecu flash FAQs by 2 Wheel Dyno Works that may help

[SXXP]

8 minutes ago, prowlnS10 said:

A decat aftermarket header flows significantly more than the oem...without a flash or other method of correcting fueling it would be very lean under certain conditions, load & rpm...snorkel removal would increase air velocity & flow leaning out the mixture as well...I am not qualified to state if it would be harmful to your bike but the result of leaner mixtures is the motor & related components run hotter & more susceptible to pre-detonation...which can't be healthy for any modern motor that already is leaner than optimal, so would not do those 2 changes on my bike.  Here is some ecu flash FAQs by 2 Wheel Dyno Works that may help

 

Thanks.  I have a header on the way, but am concerned about those upcoming forays into Mexico where you buy gas siphoned out of a drum into empty milk jug gallon containers in the middle of BFE, or for some remote areas here in the US where all you can find is 85 octane.

 

Returning the ECU for a re-flash to stock sounds cumbersome, not to mention changing back to the stock header for such trips....

Edited July 11 by SXXP

[SXXP]

On 7/11/2024 at 9:05 AM, prowlnS10 said:

A decat aftermarket header flows significantly more than the oem...without a flash or other method of correcting fueling it would be very lean under certain conditions, load & rpm...snorkel removal would increase air velocity & flow leaning out the mixture as well...I am not qualified to state if it would be harmful to your bike but the result of leaner mixtures is the motor & related components run hotter & more susceptible to pre-detonation...which can't be healthy for any modern motor that already is leaner than optimal, so would not do those 2 changes on my bike.  Here is some ecu flash FAQs by 2 Wheel Dyno Works that may help

 

I've installed headers eliminating the cat. conv. and as expected I'm getting a CEL (P0030).  The ECU goes out to 2WDW later this week.  In the interim, I tried clearing the code repeatedly, but it pops right back up.  Does the re-flash take care of this issue, or am I going to have to live with the CEL symbol on the dash?

 

BTW, I read your follow-up to the ECU re-flash on your blog, and am now concerned about the pretty drastic loss of range per tank you are experiencing.   Anyway, as I had already paid for the re-flash when I read about your real world preferences/requirements vs. what the the de-cat headers/re-flash provide,  I'm just going to go ahead with it, and see how I compare with your experience.    Maybe, I'll end up doing what you did.

[prowlnS10]

2 hours ago, SXXP said:

 

I've installed headers eliminating the cat. conv. and as expected I'm getting a CEL (P0030).  The ECU goes out to 2WDW later this week.  In the interim, I tried clearing the code repeatedly, but it pops right back up.  Does the re-flash take care of this issue, or am I going to have to live with the CEL symbol on the dash?

 

BTW, I read your follow-up to the ECU re-flash on your blog, and am now concerned about the pretty drastic loss of range per tank you are experiencing.   Anyway, as I had already paid for the re-flash when I read about your real world preferences/requirements vs. what the the de-cat headers/re-flash provide,  I'm just going to go ahead with it, and see how I compare with your experience.    Maybe, I'll end up doing what you did.

The fault code should only be generated by disconnection of the O2 sensor, not by installation of a decat header...the 2WDW flash corrects the generation of a fault code related to the O2 sensor...anytime the ecu is disconnected from the bike fault codes will also be generated (I recall it being 3 or 4 different codes). I have not had further fault codes after the 2WDW flash & clearing the codes. My blog post has been updated after a few more tanks of fuel...it is looking like I gained about 10% in mileage by reverting back to the oem header/reflash, but am still about 5% lower than oem configuration.

[SXXP]

1 hour ago, prowlnS10 said:

The fault code should only be generated by disconnection of the O2 sensor, not by installation of a decat header...

 

Yeah, I didn't reinstall the O2 sensor on the de-cat headers.  I've unplugged the sensor from the harness.  There's a bolt capping the O2 sensor hole right now - as 2WDW wants it removed for their ECU re-flash anyway.    The ECU goes out later this week. 

Edited July 30 by SXXP

[174ktm]

I have a 2021 and did a full Akrapovic exhaust/air box/, the bike would pop on decal. I had the ECU refreshed and it's fine now. To be honest, I wouldn't be doing any modifications to my next Tenere, I will just ride it as is, it's not worth the expense for the few extra HP. 

[Rider 101]

1 hour ago, 174ktm said:

I have a 2021 and did a full Akrapovic exhaust/air box/, the bike would pop on decal. I had the ECU refreshed and it's fine now. To be honest, I wouldn't be doing any modifications to my next Tenere, I will just ride it as is, it's not worth the expense for the few extra HP. 

Unless you are Pol Tarres

[712moto]

On mine, removing the cat was the single most impact-full thing I did with regards to performance. No other mods, including ECU changes, did more for the engine. Mostly increased response and low rpm performance in my case, but that is usually where my bike lives anyway. The bike has more then enough power stock, it just needs a smoother delivery down low. Now the engine just opens up more (in lack of a better term) and that little notch/jerk you sometimes get when twisting the throttle on a stock T7 is long gone.

I ran it without any ECU changes for a little while, and it seems to work OK- however it definitely runs leaner. I then put a Rapid Bike Evo with the standard akra tune you get with it, just to ensure it gets enough fuel in there. But you could probably run it for a little bit without doing the ECU, just maybe stay off WOT and not load the engine as hard, while you save up the money/get some ECU solution in place.

Edited August 1 by 712moto

[SXXP]

8 hours ago, 174ktm said:

I have a 2021 and did a full Akrapovic exhaust/air box/, the bike would pop on decal. I had the ECU refreshed and it's fine now. To be honest, I wouldn't be doing any modifications to my next Tenere, I will just ride it as is, it's not worth the expense for the few extra HP. 

 

I'm seriously second guessing my decision to re-flash.... mostly because of the need for high octane, and not because of cost, but availability in remote areas, or when travelling thru Mexico.

[Fzrcraig]

I'm missing the connection between a reflash and the need for high octane???

[prowlnS10]

On 8/1/2024 at 8:55 AM, Fzrcraig said:

I'm missing the connection between a reflash and the need for high octane???

Most flashes include adjusting ignition timing restrictions in combination with fuel & throttle mapping to extract proper fueling, maximum gains, throttle response & refinement & as such are tuned for premium 91-93 (R+M)/2 fuel....but in theory could be tuned for regular grade fuel if timing was not adjusted much beyond oem settings...but would limit some of the benefits of a flash.

Edited August 3 by prowlnS10

[Fzrcraig]

OK, but my understanding is that higher octane offsets detonation. It isn't a performance aid that can be tuned-to. 

[prowlnS10]

2 hours ago, Fzrcraig said:

OK, but my understanding is that higher octane offsets detonation. It isn't a performance aid that can be tuned-to. 

Higher octane fuel, including other additives, can offset pre-detonation, in that it has higher limits with regards to when pre-detonation occurs, thus permitting the use of more timing advance vs a motor tuned to lower octane fuel...so, in a sense, is  a performance enhancing component that can be tuned for. i.e. if  economy & lower fuel costs is desired or higher octane is unavailable then the tuner would tune for low octane fuel OR if increased performance is desired then would tune for higher octane fuel.  To address your original question, a reflash does not NEED high octane fuel, but maximizes it's benefits when tuned for higher octane fuel.

Edited August 1 by prowlnS10

[Hollybrook]

Higher octane fuel actually burns slower and has less energy. What that does for you is to allow you to run more ignition advance, enough so that you overcome the lower energy avaliable in the fuel and make more power. 

 

If your ECU is not setup to use higher octane fuel, you should not use it if you want the maximum power and economy. If it is setup for high octane, you will get better power and economy with high octane fuel. There should be little issue running a slightly lower octane fuel in an engine setup for higher octane, provided you don't run it flat out, or for extended periods. 

 

My ECU is flashed by 2WDW, so I try to get premium fuel, but I sometimes cannot find it in remote areas and run regular with no bad effects or worries. 

 

FWIW, I recall that 2WDW stated that even the stock CP2 engines run better on premium and that is what I used prior to the flash. 

[SXXP]

4 minutes ago, Hollybrook said:

My ECU is flashed by 2WDW, so I try to get premium fuel, but I sometimes cannot find it in remote areas and run regular with no bad effects or worries. 

 

Thank you!  This is a very important issue to me and it's good to hear first hand experience on this topic.  I feel better proceeding with intake/exhaust mods + ECU re-flash now.

[Hollybrook]

@SXXP you should probably email 2WDW and ask them about your specific mods and running lower octane fuel, just to be on the safe side. They are often busy and it can take a day or two to get an answer. 

[SXXP]

1 hour ago, Hollybrook said:

@SXXP you should probably email 2WDW and ask them about your specific mods and running lower octane fuel, just to be on the safe side. They are often busy and it can take a day or two to get an answer. 

 

Are you running a de-cat header?