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TunerDepot

3.5" Down-pipe for GM Duramax L5P 6.6L

$357.50

SKU: EP-GM-L5P-DP

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$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The GM Duramax L5P 3.5" Down-pipe is a direct replacement for factory units on Chevrolet Silverado and GMC Sierra 2500HD/3500HD trucks equipped with the 6.6L Duramax L5P engine. It is constructed from 3.5-inch T409 stainless steel to improve exhaust flow and reduce backpressure. This downpipe facilitates complete elimination of the factory Diesel Oxidation Catalyst (DOC).
Show original supplier description
The GM Duramax L5P 3.5" Down-pipe is designed as a direct bolt-on replacement for 2017-2026 Chevrolet Silverado and GMC Sierra 2500HD/3500HD trucks featuring the 6.6L Duramax L5P engine. Constructed from premium 3.5-inch T409 stainless steel, this downpipe enhances exhaust flow efficiency by an estimated 20% over stock, reducing backpressure and restriction. It completely removes the factory Diesel Oxidation Catalyst (DOC) for improved turbocharger performance and exhaust gas evacuation. It features a secure 4-bolt flange design with two installed studs and includes heat wrap for optimal temperature control and improved heat retention, contributing to longevity. The design is ideal for high-performance applications and intended for diesel truck owners and mechanics seeking a specifically engineered solution for the L5P platform. Please note that this Duramax L5P downpipe upgrade is intended for off-road use only and necessitates custom tuning for optimal performance and functionality. Minor adjustments may be required for 2020 and newer models.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

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Specifications

BrandTunerDepot
Part NumberEP-GM-L5P-DP
CategoryExhaust
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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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