US cars have the first cat built into the headers. And then a seperate pipe with the second cat. To eliminate the first cat, you'd have to cut the headers and weld something into place. US Headers are about $2000 for the pair.Have you or anyone heard an exhaust system with the first set removed, new x-pipe & mufflers? How loud would that be (in the car) I wonder? Yes, Jeff said he has high performance cats to replace the second set.
Exhaust comments above. Other differences (not sure what really makes a difference):What are the real differences between Euro spec and US spec on the Maserati GS ? Am looking to buy a GS in the US to import back (cheap dollar) but would like to know if there are any real differences aside from MPH on the speedometer. Thanks for any input.