4.5-Inch Cat-Back Downpipe w/ GESI G-Sport Catalytic Converter

The Active Autowerke Downpipe is engineered to significantly improve exhaust gas evacuation, leading to increased horsepower, quicker turbo spool, and enhanced durability for your BMW's B58 engine. The factory downpipe is known for being restrictive, hindering performance. This upgraded component utilizes a 4.5-inch diameter 304 stainless steel piping, maximizing flow capacity and power output, while a stainless flex joint and precise tapering ensure seamless integration with the OEM exhaust system. This specific variant features a GESI G-Sport Ultra High Output Catalytic Converter, designed to be EPA registered and OBD2 compliant for use in 49 states. It is rated for engines producing between 500 and 850 horsepower and can withstand temperatures up to 1500 F. The converter's proprietary precious metal loading technology ensures greatly reduced emissions and effectively eliminates most Check Engine Lights, providing a reliable solution for emissions compliance. The converter reaches operational efficiency within 9 seconds of startup and is covered by a 5-year/50,000-mile warranty. The downpipe is constructed from TIG-welded 304 stainless steel for maximum durability. It is compatible with 2016+ BMW M240i, 340i, and 440i models equipped with the B58 3.0L engine, including xDrive variants. **Important Note:** While this catalytic converter is EPA compliant for use on OBD2 vehicles (1996 and newer) except in California, it is not legal for use on vehicles registered in California due to state regulations. Federal law prohibits the tampering of an emissions control device; this part is intended for use in the repair or replacement of emissions control systems where emissions are not adversely affected.