---tab Description--- Black LML 4" Exhaust Overview Upgrade your 2011-2015 LML 6.6 Duramax with our 4 Inch Black Downpipe-Back DPF Delete Exhaust. It removes factory exhaust restrictions to boost power, torque and throttle response, and produces a rich aggressive exhaust sound. Made of durable 409 stainless steel with black powder coating and titanium heat wrap, it features great heat resistance and corrosion resistance. Ideal for towing, off-road and tuned trucks to gain better performance, fuel efficiency and stylish exterior look. Black 4" Downpipe-Back Exhaust Key Features Experience remarkable fuel economy upgrades with our DPF delete downpipe-back exhaust. Replacing your restrictive stock exhaust system effectively enhances overall engine efficiency, improves gas mileage, lowers daily fuel expenses, and delivers better running performance whether for heavy towing or off-road driving. Black Powder Coating for Heat and Corrosion Protection High-Temperature Protection: Professional-grade coating withstands brutal exhaust heat, preventing discoloration and heat damage for long-lasting performance. Enhanced Corrosion Resistance: Shields against road salt, moisture, mud, and off-road debris, ensuring lifelong durability even in harsh environments. Improved Aesthetics: Sleek matte black finish transforms your truck’s undercarriage, giving it a stealthy, performance-focused look that matches your Duramax’s power.. Black Titanium Heat Wrap for Head Pipe Heat Control Reduced Underbody Heat Radiation: Blocks harmful heat from damaging sensitive hoses, wiring, fuel lines, and engine components, extending part life and preventing heat-related failures. Extreme Temperature Endurance: Rated to withstand over 1000°C (1832°F) – ideal for tuned Duramax engines, heavy towing, and high-performance off-road use. Optimized Exhaust Flow: Eliminates heat soak, keeps exhaust gases moving fast, and optimizes engine efficiency for consistent power gains and smoother operation.. ⚠ Off-Road Use Only – DPF removal is illegal for on-road vehicles in most regions. For competition/racing use only. Downpipe-Back Exhaust Specification Material: Premium 409 Stainless Steel Finish: High-Temperature Black Powder Coating Heat Management: Black Titanium Heat Wrap on Head Pipe System Type: Downpipe-Back DPF Delete Application: Designed for Downpipe-back systems, ideal for high-temperature environments, towing, heavy loads, performance-tuned vehicles, and off-road use. Durability: Built to enhance exhaust system robustness and impact resistance. Installation Guide Install takes about 1hr with basic hand tools done on the ground of your driveway or garage. Quicker if you have automotive style lift. Cutting may be be required to fit shorter wheelbase bed/cab configurations. Clamps, hangers and hardware are included. You may have to re-use some factory hardware. Tuner Required for DPF Delete Exhaust Installation Removal of the DPF, CAT, SCR, and/or DOC involves removing and...