Keep the check engine light off with MagnaFlow California Grade CARB Compliant Direct-Fit Catalytic Converter 452431. 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. Designed to fit the 2001-2003 BMW 530i and 2001-2003 BMW 525i, this direct-fit catalytic converter also interchanges with OE parts 18 40 7 514 499 and 18 40 7 507 348, among others. 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 California Air Resource Board requirements, and has undergone additional testing to comply with CARB guidelines to allow for legal use in California and CARB restricted states, for the listed vehicles.