B58 Catted Downpipe

The Active Autowerke BMW B58 Catted Downpipe is engineered to significantly reduce exhaust back pressure, leading to quicker turbo spool and improved horsepower and torque for your vehicle. Constructed entirely from TIG-welded 304 stainless steel with 1.5MM wall thickness, this downpipe is built for durability and a long lifespan. It features a 4.5-inch diameter piping that tapers to meet the OEM exhaust system, ensuring compatibility without reducing the stock diameter at critical points. This downpipe includes an Active Aflow catalytic converter with a 400 cell per square inch density and 304 stainless steel construction, including the substrate. This high-output, EPA-registered converter is compliant in 49 states and fully OBD2 compliant for 1996 and newer vehicles, designed to prevent catalytic efficiency-related Check Engine Lights. The converter is rated for engines up to 800 horsepower and utilizes proprietary precious metal loading technology for reduced emissions. A key benefit of this downpipe is that NO PERFORMANCE TUNE IS NEEDED. The product is covered by a 5-year/50,000-mile warranty on the shell and tube ends, and a 2-year/25,000-mile warranty on the catalytic core. Please note that fitment applies to US model cars only unless specifically stated. Additionally, these catalytic converters are not legal for use on vehicles registered in the state of California. Federal law prohibits the tampering of emissions control devices; this aftermarket part is intended for repair or replacement where emissions are not adversely affected. The warranty will be null and void if the car has excessive burble, as this can physically destroy the catalytic core.