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Going back to OEM exhaust

14K views 29 replies 10 participants last post by  tooter 
#1 ·
First off I know I’ll lose some performance but, I want to give this a try. If I were to go back to the OEM exhaust removing the Two Brothers Tarmac would it work ? Could I unplug the O2 sensor from the auto tune module, turn off the auto tune and run the bike on the current map the PCV has in it ? It would have no O2 sensor connected to the PCV / ECU at all. The bike would just be fueled by a map the auto tune had generated with the Two Brothers installed. Would this even work ? I ask because I’m just sick of the D*** noisy exhaust.
 
#7 · (Edited)
If you want to go back, I highly recommend this free stock exhaust mod. :)

Land vehicle Vehicle Motorcycle Motor vehicle Car


Auto part Vehicle Grass Plant Engine


Grass Plant Auto part Lawn Vehicle


This is how it sounds...



The sound is just deeper and a tad bit louder than with the muffler. I'm not sure how much performance I gave up as the engine runs really good this way. The exhaust is also about one third lighter without that big heavy ugly muffler. It's all tucked away under the bike and nothing sticks out.
 
#14 ·
If you want to go back, I highly recommend this free stock exhaust mod. :)

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This is how it sounds...



The sound is just deeper and a tad bit louder than with the muffler. I'm not sure how much performance I gave up as the engine runs really good this way. The exhaust is also about one third lighter without that big heavy ugly muffler. It's all tucked away under the bike and nothing sticks out.
I like this idea sound soft and not loud like my 2014 groms finbro full exhaust. The box under the grom is just the CAT system. If I do get a newer grom I will remember this video. Thanks for posting the sound video
 
#12 ·
Your PCV map would only be good for the open loop if you disconnect the wideband. No wideband and the stock ECU would be shooting for a 14.7 AFR in the closed loop. Get a new bung welded to the stock exhaust and let wideband continue to control your closed loop.
 
#13 ·
Oh wait you have a flashed ECU don't you, scratch my last post then...cause I don't know, lol.
 
#15 ·
You could just get a metal strap to replace the broken mount.
 
#30 ·
You could likely get your friend's stock SF exhaust for next to nothing if you want something cheap and quiet but with just a little more sound and performance. Most guys throw them away once they get an aftermarket exhaust.
 
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