cat removal

If you remove the cat and get defected its 67 dollars in south australia to go and get the defect off does anybody really know if there is a fine and i mean do you know somebody who has got one the fine i mean cant you just say thats how the car came when you bought it and you didnt know ,especially if the resonator is still on and car is mostly stock .I suppose it might help if your an old bastard like me at 40 and dont have badges all over the car my car goes like stink but looks stock other than the ss 3 inch straight through muffler. Doesnt it come down to attitude if you get pulled over.