2020-2023 Duramax L5P DieselR Downpipe Back Exhaust Single No Muffler (255-01400)
Built for Strength. Engineered for Performance.
Upgrade your exhaust system with the DIESELR Downpipe Back Exhaust, designed for 2020-2023 GM 2500/3500 6.6L Duramax L5P. Built from T409 stainless steel, this system enhances airflow, durability, and horsepower, making it a must-have for serious truck owners.
Why Choose DIESELR?
✔ Heavy-Duty Construction – Mandrel-bent T409 stainless steel ensures maximum durability and a perfect fit. ✔ Leak-Free Connections – High-quality flanges and pre-welded contour-bent hangers for a secure installation. ✔ Hassle-Free Install – Includes all necessary clamps and hardware for a straightforward installation.
Performance Benefits:
✔ Increased Horsepower – Improved exhaust flow lets your Duramax breathe better and run stronger. ✔ Lower EGTs – More efficient exhaust flow helps reduce exhaust gas temperatures, keeping your engine cooler. ✔ Deep, Aggressive Sound – Get a throatier exhaust note that commands attention.
✔ Designed for 2020-2023 GM 2500/3500 6.6L Duramax L5P. ✔ Compatible with EC-CC/SB-LB-Dually cab and box configurations. ✔ OEM-Style 4-Bolt Flange – Ensures a secure, factory-like fit. ✔ No Bungs – Allowing for customization based on your specific needs. ✔ Important Fitment Note: This system ONLY fits models equipped with the OEM-style 4-bolt flange off the turbo direct pipe.
Off-Road Use Only – Requires aftermarket tuning and is intended for competition use only. ⚠ Regulatory Compliance – Installation on emission-controlled vehicles may violate local laws. Check regulations before installation.
Order Processing Time:
Orders are typically processed within 24-48 hours after the order has been placed.
Custom or special order items may take longer to process, typically 3-5 business days depending on the product and customization required.
Shipping Methods:
Standard Shipping (3-7 business days)
Expedited Shipping (2-3 business days)
Express Shipping (1-2 business days)
Packaging:
All parts are securely packaged to better prevent any damage during transit. Fragile or high-value parts will be packaged with additional protective materials, such as bubble wrap or foam padding.
Shipping Rates:
Shipping rates vary based on the size, weight, and destination of the package. You can view the estimated shipping costs for your order during the checkout process before placing your order.
Order Tracking:
Once your order has been shipped, you will receive an email with the tracking number and carrier information. You can also track your order status by logging into your OCDiesel account.
USA Shipping:
We ship to the USA! Please note that USA shipping rates and delivery times may vary based on destination. Customers are responsible for any customs fees, import taxes, or additional charges that may apply.
Not all products are stocked in-house. To ensure you receive your desired items promptly, please check for availability before placing your order. Some products may be backordered due to high demand or supply chain constraints, which could result in longer delivery times.
We strive to keep our inventory updated regularly, but availability can change quickly. For the most accurate information, contact the OCDiesel customer service team using either this link, or the chat bubble on the bottom right of this page.
Most items are eligible for return within 30 days of shipping, provided they are unused, in original manufacturer packaging, and in resalable condition. All returns & cancellations are subject to restocking and cancellation fees.
Returns must include a Return Authorization Number (RA #) and be shipped with tracking. Return shipping costs are the responsibility of the customer.
Custom/special orders, electronics, and digital goods are final sale—no returns, refunds, or exchanges.
For full return instructions, fee details, and conditions, click here.
