Last night I brought my evo to the muffler shop to see if they know why my HKS Legamax sounds 100% like stock(friends and I dont notice a difference at ALL). So the guy in the shop looked under my car and said that it has a California catalytic converter(the first owner of the car bought the car when he was in cali). So I'm just wondering is that one of the reason why my car is not so loud? If so what do I need to change to notice more changes(other than a test pipe)