New here and need help for me Getz
 

G'day all, I've got a 2005 Getz that's decided to suddenly loose it's poke and the exhaust sound has changed out the back to a tryhard sport sound(more muffled I guess is another way to describe it). Done all the usual checks and found nothing not even an exhaust leak. No engine warning light has came on but could it possibly be the cat converter on its last legs/slightly blocked? Any help would be appreciated if anyone else has experienced this.
Cheers