!! please help !! I have recently purchased a 2006 VZ 3.6 wagon. I took it down to an exhaust shop because it was making a raspy sound. They assured me they could fix the problem but they made it worse. They cut the 2 rear mufflers off and replaced with straight pipe and replaced the end muffler with a coby/hotdog. Then told me the previous owner had removed both catalytic converters now they say the only way to get rid of raspy sound is to replace catalytic converters or run 2.5 straight pipe from where catalytic start to rear muffler. located in nz so its legal to have no catalytic converters What would be the cheapest option to fix?