Seems like the Aerio with the J20 has 2 Cats. Liana with the M13 has one downstream. Here's a snap from the workshop manual:

My car has done 120K Kms Mashallah and the throttle response and the sound is unmistakably clogged Cat. The valves are fine and so are the rest of the things in the intake. Time to remove some restriction from the exhaust 