MagnaFlow HM Grade Federal/EPA Compliant Direct-Fit Catalytic Converter 50434 helps keep the check engine light off. DIY installation is easy with the proper tools (no cutting or welding required). With features including mandrel-bent tubing to eliminate flow restrictions and stainless steel construction to resist corrosion, you can have confidence in the quality of this catalytic converter. Using state-of-the-art 3D scanning systems in the design process, the MagnaFlow metrology department ensures this new part to fit and function like the original equipment. This direct-fit catalytic converter is designed specifically for the 2006-2009 Cadillac STS. The included gaskets & hardware reduce the possibility of a leaking seal while avoiding the need to reuse corroded factory parts for installation. This replacement part is designed to meet or exceed Federal emissions requirements set forth by the EPA, complying with legal standards for OBDII Federally registered vehicles with Federal/EPA Emission systems