Gents, I have 'a friend' who decatted his 2011 RGU. I'd NEVER do that myself because I don't want to kill the trees, bunnies, etc... LOL.

Anyway, the bike has been running like CRAP since decatting. It's been surging underway, hard starts, fouled gas-smelling spark plugs.

This is just a cautionary tale for anybody else planning on de-catting their 2011's. He's ordering a tuner today and HOPEFULLY that will fix it for him.

Makes me wonder if anybody went with American Customs decatted pipes if they had any issues like my friend has...

 

[QUOTE=timinfla22;8236128]Gents, I have 'a friend' who decatted his 2011 RGU. I'd NEVER do that myself because I don't want to kill the trees, bunnies, etc... LOL.

Anyway, the bike has been running like CRAP since decatting. It's been surging underway, hard starts, fouled gas-smelling spark plugs.

This is just a cautionary tale for anybody else planning on de-catting their 2011's. He's ordering a tuner today and HOPEFULLY that will fix it for him.

Makes me wonder if anybody went with American Customs decatted pipes if they had any issues like my friend has...[/QUOTE
I just did mine this weekend, I installed a thundermax and it runs excellent! A tune is a must!!!

 

[QUOTE=viperr817;8236243]Thank you VERY much for the update, Viper. Would you please tell me a bit more about what you did in detail so I can follow suit?

 

Don't even think of changing pipes on pollution controlled vehicles without a tune.

 

Removed my CAT on my 11 Limited, no problems at all. I bet he has an exhaust leak at the head or somewhere else. That would cause these problems. Just removing the CAT isn't going to cause this. I wonder if he got the O2 sensors back in the right spot. No tuner is required, the stock ECM will compensate for exhaust changes.

 

[QUOTE=timinfla22;8236259]I got a set of 09 headpipes, had them jet hot coated, installed dragtron aircleaner thundercone slip ons, and bought a thundermax thru a dealer and the dealer had them pre load a base map. It is like a totally different animal now. I have a vid on YouTube search viper817 and u can watch. I'll post a link later when I am on a computer and not my phone. BTW if u did not know 09 pipes did not come with cat in them and have o2 sensors that are bigger and closer to exhaust flanges, which are necessary for the thundermax.

 

From what I understand, is the cat provides most of the backpressure. Also the existing o2 sensors are not wide band type, so I doubt the ecm will be able to fully compensate. I could be wrong though. I do know leaving cat and installing slip ons only is fine, as I did this prior to changing headpipe.

 

My dyno tuner says he's worked on a bunch of bikes that have had that done. Here's what he had to say about it:

When you remove the cat on the bikes with the 12mm 02 sensors in the collector, the cat no longer keeps the exhaust flowing in a straight path down the pipe. The gases swirl around in the collector, and the 02 sensors get "crosstalk." That means that at times one sensor is getting readings from the other cylinder, or a mixture of both cylinders' gases. The bike's ECM attempts to make corrections, but it gets worse over time.

He found out because he was fighting a bike that ran great when dynoed, then started running worse and worse in the following days. I forget how many times he attempted to correct the maps, but in the end all was fixed when the customer swapped exhausts.

It does not matter for '09 head pipes, as the 18mm bungs are right by the exhaust port.

YMMV

 

That's complete BS. The front O2 sensor sits in the front pipe and the rear O2 sensor sits in the collector. It appears that they both sit in the collector but in actuality the front pipe extends into the collector. I just did mine and have had no issues at all. They are isolated this way to prevent this. Lots of folks have done this with no issues including me.

 

actually he is right. Here is a conversation I had with Doc of Docs performance and he knows more about tuning then most will ever know. (I originally thought like you when I removed my cat by the way)

This is jeff from Montana. I have a quick question about cats in headers on the newer touring bikes. I have had some guys tell me that the cats have very little influeance or effect on afr's and I have others say that if you remove the cat you will go way lean. Some say it flows well others say it is a bottleneck. I know you probably have some real world expereince with this so just want to hear what you have to say. thanks and Merry Christmas

Jeff
First off it depends on what year bike you want to remove the cat from. The 09 model can be removed without issue however when you free up the flow in the pipe and install an air filter a tune will be necessary. This is like anything else Jeff....free flow a/a and exhaust without a tune will run leaner.
The 2010 and 2011 with the new style 02 sensors can not have the cat removed....if you do the 02 sensors will cross talk and you will never keep the bike intune. In these bikes the head pipe has to be replaced with a new header system....I highly recommend the JackPot ''X'' pipe from Jamie at Fuel Moto, this is a great pipe that fits well, very well built, performs GREAT, and uses the stock heat sheilds....plus it comes with both new and old 02 sensor bungs.
Removing the cat will make more power and the bike will run MUCH cooler. With the Jackpot ''X'' pipe and a good A/C you will see a 14/14 gain on an average.
I just did a 2010 ultra with Jamies pipe, Big Sucker, Andrews 26 cam, Rinehart slip-ons.....stock was 62/78 .... now he has 86/98. I did another 2010 ultra a couple months ago with Jamies pipe, kept the stock mufflers, 26 cam, SE air filter, and we got 85/94 (with stock mufflers)
Good to hear from you Jeff Doc
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Doc

Doc, I cut open a set of 2011 headers today (got a freebie set of take offs) just to see what the cat looked like. After removing the cat material it looks like the 02 sensors are well protected from each other as an exhasut tube seperates them inside the cat chamber. Thanks jeff

Jeff
There is one 02 sensor that is in a tube and but the other is not protected because it is in the big void that the cat used to fill. The Cat provides enough back pressure to protect the one sensor in the big area and the cat stops 99% or the reversion (negitive pulse wave) coming back up the pipe. When you remove the cat reversion takes over taht void and the 02 sensors will now cross talk........I know this for a fact Jeff I'm not guessing or blowing smoke. Both 02 sensors have to be in a tube at least 6'' to stop the cross talk.
Doc
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Re: cat in stock headers.
« Sent to: Jeffd on: December 17, 2010, 03:24:35 PM »
« You have forwarded or responded to this message. » ReplyQuoteDeleteNo Jeff it won't in this case because the two tubes are going into a common area which will allow the gasses to enter either and/or both tubes with the slightest reversion. When you have a two into one collector you have a small area before the collector....this speeds up the exhaust to exit the pipe and hinders reversion pulse waves to enter the two pipes.
You're going to have to shoot the lock off your walet and get a good header like the Fuel Moto Jackpot X pipe.....you won't be sorry.
Doc
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