Can anyone explain what I should experience if I simple replace stock exhaust with R77 system and what about the 02 sensor ? I have a very stock 2013 1441 with 5000 miles.. reason for changing exhaust was weight and appearance .
Thanks

* Last updated by: chrly on 10/16/2015 @ 5:47 PM *

The 02 sensor you have two options. Either get your ECU flashed to mute/disable any codes or get a bung put on the exhaust to run with it. Not sure which I'd go with, these days I'd keep the 02 sensor if the bike was so equipped as if you ever get something like autotune it'll be required. You could have a shop install a bung or install one yourself if you have the knowledge & tools.

Some exhaust come with the bungs, I believe TB does. I don't recall seeing any version of R77 that came equipped with one.

As far as the exhaust itself, was a bit of a pain to install the headers (they are not welded in place) but overall a fairly simple job doable in a few hours.

Thanks for the response...

Run with the 02 in play. The ignition change alone is probably the main problem of running in limp mode. Flashing the 02 to turn the light off means the method is set with light on or not. You removed a sensor so the bike defaults to a 'save the engine' kind of detuning. "We take measures..." which means to see your dealer and have said sensor repaired/replaced/etc.

You'll experience a slight uncorking of the pump speed moving faster. The air speed out of the exhaust and all that proportioned to intake speed, plus the 'power to weight ratio' you changed, it begins to add up. When the intake and exhaust valves are in that opened transition, air speed is going to clean out the fresh charge more than it did when clogged up with the stock exhaust.

You're not about to lean out so as to be scared of damaging the engine, just more detuning you'll have to address or not. Where are we going with the tune? Weight and looks and we are done? So be it. A forum member asked if running the header alone was going to hurt the engine and I said no, go for it. As far as I know, no damage to the engine, just damage to the ears. I heard he reinstalled the mufflers again and that's the last I've heard. So those 77's won't hurt a fly, if we compare it to a slightly leaned out condition is just less tune ignored.

Back to the 02 and Vic's suggestion about autotune. Of course with this model you have autotune as another option or in other words; running both in open loop and at closed loop sessions. This is where you live with the check engine light being on, the ignition curve, sub, fuel, if not the lower dash area blinking setting the backup [who cares]. Install the autotune and tune the bike from there. Save the map. Improve the settings when you see how it was captured, save those settings, or stick with the calc of the map made; run the auto-map minus the 02 in the loop, autotune is no longer in the loop. Or... Uncouple the pc out of the loop, install the 02, the 77's could care less with or without the tune.

Sound doable either way? Yes, [imo].

Hub question for you? If someone has a bike with O2 sensor, and they have a O2 ecu of course. Our 14Rs either have ECU part 27115-0838 (49 state US) or 27115-0839(CA/O2 sensor). CA bike is also going to have the emissions cannister.

Could someone just replace 0839 with the 0839 ECU to eliminate any O2 sensor issues?

The 38 is a CNUS (Canada-US) open loop ECU = under seat atmo sensor.
The 39 is a Cali open loop ECU = atmo sensor-same location.

Euro/UK/FRA/AU/MAL are closed loop = (02).

Could someone just replace 0838 with the 0839 ECU to eliminate any O2 sensor issues?

Both use same 'backup method' math'd to that sensor dropout. But the wire harness has to be different; where the under-seat connector is eliminated and the 02 [am going to guess past a 3-wire atmo connector is the 02 has a preheat wire] so that adds wire and a change in harness, change in triggering the DTT; is my guess.

The 02 is in a constant fluctuation of changing fuel trim, whereas the atmo just sits there with the same number being sent in, or is waiting for a change in altitude pressure to move a few points in voltage. Where the 02 is in a constant holding pattern of 14.6 AFR in stoic, give or take a point, where open is set it where you want it in any AFR setting. So by removing the 02, there is the loophole of resetting the jet cut with the pc.

Where the backup has sent a signal out to the injectors, but the pc now receives an input, changes to the output and resets the injector time. The autotune comes along, cleans up the 'averages' by using the tic-tac-toe of those [cell block] numbers surrounding the number you set sort of [autotune] begins to math the averages in the north-south-etc next to each other is average those numbers out as you go.

Which brings me to ask or begin to try and walk the DTT... look how there was no effect with Yanni's 02. That ECU is preset to flip to a flop if the math does not compute. If I run an 02 ECU, might it just be a difference in 'pin not used' is now being used?

Again, kawi uses 3 trigger signals to the ign/subs/anshit, where the others use a 2 hit limp you go messing with the preset. You'd have to run an ignition curve piggy daisy chained off the pc, the autotune daisy chained off the ign-curve box, the factory 02 out of the loop for the pc's 02.

That's basically watt you see is what you get. Interchangeable ECUs is my guess.

Signed,

Pinot Used

* Last updated by: Hub on 10/17/2015 @ 2:11 PM *

Not sure which I'd go with, these days I'd keep the 02 sensor if the bike was so equipped as if you ever get something like autotune it'll be required

I have a Euro model that also has std O2 sensor. Changed exhaust and welded a bung in.
I use a PCV with an auto tuner. the auto tuner comes with its own O2 sensor that you have to fit over and above the std sensor. Powercomander recommend using an optimisor to allow closed loop tuning. Not sure if this is only relevant to Euro spec or all models with factory fitted O2 sensor. After flash I removed std O2 sensor and optimisor otherwise it stutters (same experience as Yannih) plugged the hole with a stainless bolt, and now only use the Autotuner O2 sensor.

I did however try it without the std O2 sensor before I flashed and as Hub says the yellow engine warning light came on, but admittedly didn't ride it long so can't say if there was any difference.

Untamed thanks...I did not know that. I thought the autotune required an O2 but not it's own... I thought that was for people like me who's bike didn't come with O2 at all.

Interesting!

Ok folks.. Just to follow up on this thread.. I replaced teh stock system with a Yosh SS system.. No sensor on the stock pipe . I personally did the R&R..My bike is a 2013 sold, zero miles to me , new in October this year in California .
I am confused but not enough to worry about :)

Pretty sure there is no O2 sensor on my '14 CA model I purchased new? Is it hiding somewhere? If so maybe I can go PC V w/ auto tune .....

EDIT .. no O2 sensor on my CA 14R

* Last updated by: cruderudy on 12/25/2015 @ 3:20 PM *

Not to long after I got my 14 I called Ivan and talked at length with him which mods to make. Ivan has tested exhausts using just the cans and also with full system. Seems the stock header works pretty good, only a couple of HP difference on top end. Considering the cost to benefit ratio and what it takes to replace header I would certainly ask myself if it was justified.

I fitted the Yosh R-77 cans only, no header, super pleased with sound and looks, used the money I saved on header and bought other "extras" for my bike. With flash, pcv and Ivan's map, Yosh cans, I have a strong running bike that is streetable and will run with just about any of the Big Dogs.

Spend your money wisely and you will be happier with the end result!

Rkt the only reason I went with full system was I prefer the single sided look. Also I like the additional weight reduction. For people that like/want dual exhaust you're right, really no reason to pay for headers unless going with titanium. If someone has the tools they can even plug the stock header for a single sided exhaust.

Crude.... I am now thinking that we must have non-calif specific bikes that were sold in Calif regardless of the O2 sensor..? I waited a month to put my exhaust on trying to figure how to get around the O2 sensor only to find out it does not have one, at least in the exhaust system. Going to see if I can locate ECU serial number.

system. Seems the stock header works pretty good, only a couple of HP difference on top end. Considering the cost to benefit ratio and what it takes to replace header I would certainly ask myself if it was justified.

Not to hijack your thread. I ask the same question. There are so many different opinions on the forums, and whilst I agree that there is hp increases from standard canisters to aftermarket. How much hp difference is there between 4-2 vs 4-1.

If there are those that have actually tried and tested the difference and would share their actual findings that would be great. or if it has already been posted, then direct me to the post.

* Last updated by: untamed on 12/26/2015 @ 12:10 PM *

Untamed.. I aways try to have documentation available.
I try to have dyno runs as close as possible or at least the same dyno. Fortunately for me TEKMOTO opened prior to my getting my ZX14. Taylor is very knowledgable and easy to talk with.
We ran a base run as soon as I found out he had opened the shop.The 14 had about 5000 miles on the odometer. Then I found a buy on a Yosh R77 full system ( $680) IIRC. I hesitated installing because I was confused about teh O2 sensor.. When I did decide to go ahead and make the switch, I bought teh Dynojet Quickshifter and PCV as I am drag racing the 14. After pulling teh stock exhaust system, I was really confused because I found no sensor. That eliminated installing one on the new system obviously . Here are teh runs. Pretty tuff to distinguish hp differences..

* Last updated by: chrly on 12/26/2015 @ 4:23 PM *

Vic, I love the single sided exhaust, sometimes wish I had one too!!! I went with just the two cans for a couple of reasons. First, at 6' 2" and 245 saving a few pounds really wasn't going to make much difference for me. Two, I didn't really have a good place to work on my bike at the time, said screw it and just added the cans, content with my choice, for now.....

Just noticed in your signature line you have "CBlast flash (not recommended), if you don't mind me asking, why?

Like ya say Rkt, it doesn't make that big of a difference either way. Looks and sound were number one for me. If you were so inclined you could always plug the LHS and make it a single. I would've honestly considered that if I had the tools and know how, which I don't. I don't have fab tools (welder etc.) and haven't welded anything since shop class 25 years ago!

CBlast not recommended... Your text to link here...

* Last updated by: VicThing on 12/27/2015 @ 8:31 AM *

Vic, first let me say WOW!!! As an engineer I live by exact data, I'm not easily impressed by a lot at my age, and I stand by the laws of physics. The way you performed your test was exacting and impressive, numbers don't lie, people do.

I had not seen your thread because I had been off the forum for so long. Wish I had still been in Indiana, would have been interesting to use your stock ECU, CBlast ECU, and then my Ivan's ECU for your test. (Which I would have been happy to loan to you)

This is just a curiosity question which you don't have to answer, where did you do your test? In 4th gear my bike will run 170+, have +1 front sprocket, would need a long open space to turn it loose even with stock gearing. Again just curious.

VERY well done!!!

Thanks Rkt, I'm highly trained in the area of problem solving and testing. Indeed I wanted to be as objective as possible to eliminate discrepancies. It's a simple, repeatable test without a lot of variables. I'd rather not say where the test was conducted.