read through some threads and cant really find anything solid. i keep getting cat codes so i figured id replace them and considering my dad knows somw welders it should be mostly just money for parts. should i go to oe cats or magnaflows or what??? personal expierences please. i have true duals into flowmaster 40 and soon to be turn downs. so it runs and sounds great dont want to lose any performance or sound. if anything gain sound. thanks