On various 790 Duke forums, there is lore that KTM "designed this engine around having a cat, and removing it will decrease power", which of course strikes me as rubbish: the cat impedes exhaust flow and numerous tests have confirmed that exhaust restriction doesn't necessarily increase torque. I know that Coober has a tune for the 790 Duke. I have spoken to the Rotweiller guys and they are preparing a Power Commander tune for the 790 Adventure. I see that Arrow and others have made a cat-delete mid pipe. What I would like to know is if there is some consensus around the best route for cat removal and the required tune.