I'm not sure, but I found this when I was trolling the Borla internet site and found this on their Q&A:
Q. Will it void my factory warranty?
NO. Some cars even have BORLA systems as the OEM exhaust. All of our street exhaust products are 50-state emissions legal. Our headers are 50-state legal and C.A.R.B. approved. In fact, it is illegal for a dealer to deny you the OE warranty because you have changed the exhaust system [emphasis added].
If your vehicle manufacturer fails to honor emission/warranty claims, contact EPA at (202) 260-2080 or www.epa.gov. If federal warranty protection is denied, contact the FTC at (202) 326-3128 or www.ftc.gov. For additional information, check out the following links:
No. It Will Void The Warranty As It Applies To Whatever Item You Have Modified, ie They Will Not Fix Your Magnaflow Muffler If A Weld Comes Loose, But Legally Cannot Effect Coverage Of Any Other Part On The Car. I Believe It Is
SEMA That Has Fought For This Protection, As They Have An Interest In You Modifying Your Car.
BTW: I'm A Magnaflow Dealer And Have Installed A Few. Good Choice. MAKE SURE You Go With An All Mandrel Bent System. Do Not Settle For Typical Corner Muffler Shop Crush Bends.