Exhaust can to the left following the pipe in this photo, and you find it below the rear spring. Size of a big 'ol just of motor oil on it's side. Just below the clamp labelled with a "2" below. Context shot: Forgive me but I'll show you on the 790 duke (same engine/cat) because it's more exposed and easier to spot. Follow the headers down and across the bottom of the engine and you'll see the cat's ass. It rises up and then you can see it exiting left towards the exhaust can. And if you can now picture it's place in 3 dimensions, the photo below reveals the space it is supposed to fit into, but in it's place is a cat delete mid pipe.