[Hammerhead]

When my servo fried in traffic, the motor went into Limp mode, wouldn't rev over 6500 rpm and the cruise control wouldn't function until I removed the servo, placed the dongle and had the dealer clear the error code which said "MTC ERROR". I would get it hooked up to the dealer's nanny computer to see what's up.

 

[Hammerhead]

At one time, it was thought the flapper was a tuning device to widen the powerband, but the fact that it's actuated at the exact rpm as the Euro sound test sorta gives it away that it's a sound attenuation device. As for removing the flapper, the catbox itself is a much larger obstruction, so why bother? If you do a decat, the flapper remains with the cat.

 

[Hammerhead]

.I've got the Gen 3 2020 Superduke R, I'm running the stock exhaust and cat-converter with ONLY an austin slip-on.
Can anyone tell me if using the heal tech device and removing the servo motor will cause any...
1. loss of power or torque on the bottom, mid, or top end ?
2. Also is there any noticeable exhaust/sound change, low mid or top end?
Just wanna know what to expect, Thanks!

A little more sound at the rpm the flapper closes when the servo is operative. Doubt there's any loss of power. If you leave the cat in place as well as the factory silencer, it will still be plenty quiet. I think the cat muffles more than the muffler.

 

[Hammerhead]

The servo motors tend to seize up, as do their operating cables, from the extreme heat coming off the rear of the engine and coming up off the catalytic converter. If yours is operative, the only incentive for removing it is the anticipation of its demise, the code it throws and the mode it sticks the machine into until repaired or replaced and code wiped at the dealer.

Just adding a slip-on has very little effect on anything other than a (probable) slight change in exhaust tone and a possible slight weight reduction. And a different look. The catalytic converter does most of the sound attenuation and its removal makes for the biggest change in exhaust sound. The stock muffler isn't restrictive or very noise reducing because it doesn't have to fill that role. Removal of the catbox (and thusly the exhaust flapper, which provides max sound attenuation at 5500 rpm) reduces weight, increases exhaust volume and reduces residual heat felt by the rider. Not to mention opens up the most restrictive part of the stock system.

Mine tied up 600 miles from home, throwing the ECU into Limp Mode, which restricts horsepower to a max of around 100 bhp and also disables the cruise control, something I desperately needed due to a (now surgically repaired) right hand crippled with arthritis. Upon arriving at home, I immediately ordered an ESE and made an appointment at the dealer to get the code removed. A lot of hassle that could be avoided simply by unplugging the servo and plugging in the ESE. The catbox can remain in place, if so desired.

 

[Hammerhead]

Thanks for the reply mate. So no improvement in performance. Was it loader???,why do it then??, reduce weight and clutter maybe
I was hoping it might make it sound and performance better. Probably won't bother then, thanks.

It's louder at 5500 rpm, the engine speed at which the flapper partially closes, which is, incidentally, the rpm at which the Euro sound test are taken. As long at the cat box is in place, there won't be an appreciable difference in overall sound level. The flapper exists to mitigate the volume level at test rpm. It has ZERO to do with performance and technically may even inhibit performance as it's a partial obstruction in the exhaust. Eliminating the flapper by removing the cat box it's a part of reduces weight by about 15 lbs. and makes the residual heat coming off the engine a bit more tolerable. And it will be louder at all rpm levels. Just plugging in the ESE dongle only stops the flapper from partially closing at test rpm.