Black 4.0" Downpipe-Back Exhaust for 2020-2025 L5P 6.6 Duramax DPF Delete Kit | SPELAB

---tab Description---

Black L5P 4" Exhaust Overview

Fit for 2020-2025 L5P 6.6 Duramax, our 4-inch black downpipe-back DPF delete exhaust replaces your restrictive stock system to boost engine horsepower, torque and throttle response, paired with a deep, aggressive exhaust sound. Built with durable 409 stainless steel, black powder coating and titanium heat wrap, it offers excellent heat and corrosion resistance. A great upgrade for towed, off-road and tuned trucks, it improves overall performance, fuel efficiency and undercarriage styling.

Black 4" Downpipe-Back Exhaust Key Features

By replacing the factory restrictive exhaust setup, SPELAB L5P 4.0" Downpipe-Back optimizes overall engine operational efficiency, boosts gas mileage, cuts down long-term fuel costs, and ensures stable, superior performance during heavy-load towing and off-road adventures.

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 eliminating emission related sensors. A DPF delete capable tuner is required to prevent any check engine light or diagnostic trouble codes from setting.

---tab Fitment---

L5P Duramax Downpipe-Back Exhaust Fitment

• 2020-2025 L5P 6.6L Duramax Diesel GMC Sierra 2500 HD
• 2020-2025 L5P 6.6L Duramax Diesel GMC Sierra 3500 HD
• 2020-2025 L5P 6.6L Duramax Diesel Chevrolet Silverado 2500 HD
• 2020-2025 L5P 6.6L Duramax Diesel Chevrolet Silverado 3500 HD

Crew cab short bed & crew cab long bed. This will NOT FIT the 3500/4500/5500 Cab & Chassis commercial style truck.

If you need 4.0" Downpipe-Back, you can click HERE to purchase.

---tab Shipping & Returns---