Keep the check engine light off with MagnaFlow OEM Grade Federal/EPA Compliant Direct-Fit Manifold Catalytic Converter 49771. With features including free-flowing mandrel-bent tubing and highly corrosion resistant stainless steel construction, easily install this converter yourself using the proper tools, no cutting or welding required. MagnaFlow's state-of-the-art metrology department uses the latest 3D scanning systems during research and development, so you can be confident that your new part will fit and function like the original equipment. By replicating the OE design, the single laser fusion weld greatly reduces the possibility of a leak, and our compact, low-mass design also allows for greater thermal efficiency. This Direct-Fit Manifold Catalytic Converter is designed to fit the 2004-2005 BMW 525i 2.5L & 2004-2005 BMW 530i 3.0L. MagnaFlow 49771 includes (2) Nuts, (2) Bolts, (2) Flat Washers, (2) Flange Gaskets and interchanges with OE parts 18 40 7 523 904. 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 California or Federal/EPA Emission systems.