Dieselr Aluminized Cat & DPF Race Pipe | GMC/Chevy 6.6L GM Duramax LML (2011-2015)The Dieselr Aluminized Cat & DPF Race Pipe (20112015 6. 6L Duramax LML) is designed for GMC Sierra and Chevy Silverado 2500 3500 HD owners who demand a reliable, high flow exhaust solution built for performance and longevity. Made from heavy duty aluminized steel, this race pipe improves exhaust velocity, reduces restriction, and helps maintain cooler EGTs under load. Each Dieselr pipe is mandrel bent for consistent flow and precision welded to ensure