I have a 06 CTS with a 2.8 ( I know but they didn't have what I wanted in a 3.6) When I went and I got impatient. Anyway just replacer rear bumper with a V bumper. Now I need exhaust. No one knows how to change the car to dual exhaust. Called the dealer they said I can't change the cats. Meaning I couldn't put V exhaust on the car cause the computer will freak with V8 cats. Someone else told me to put V exhaust from the resonater back. The exhaust shop wants to make a Y pipe behind what I think is the resonator and fabricate new exhaust from there( and empty my wallet at the same time). Anyone have any suggestions. Please email me "vekios@aol.com" Thanks for your help...