FITMENT
- 2017-2023 6.6L Silverado & Sierra Duramax L5P 2500HD 3500HD Diesel engine trucks.
- Note: Will NOT fit Cab & Chassis commercial-style trucks.
DESCRIPTION
Product Overview
- The factory downpipe on 17-23 Duramax L5P trucks is a major performance choke point. To bypass tight firewall clearance, the stock pipe was severely stamped and flattened into an oval shape.
- This restrictive design traps intense heat right at the turbo outlet, choking exhaust flow, slowing spool-up, and raising EGTs.
- Upgrading to our massive, 3.5" mandrel-bent downpipe maximizes exhaust flow right from the turbo outlet, rapidly dropping EGTs and allowing the turbo to spool up much faster.
Key Features
- Heavy-Duty Wrapped Protection: Crafted from high-grade 304 stainless steel and wrapped in premium heat-insulating sleeve to safeguard surrounding engine bay components.
- Massive 3.5" Flow: Replaces the restrictive, "pancake" factory pipe with a true, consistent 3.5“ mandrel-bent round diameter through every turn.
- Massive EGT Drop: Expels scorching exhaust gases rapidly away from the turbo, significantly lowering under-hood heat and promoting engine longevity.
- Bung-less Design: No unnecessary sensor ports to plug, perfectly matching the original L5P factory configuration for a true plug-and-play install.
FAQ
Q: What are the main benefits of upgrading to a 3.5" downpipe?
A: The original factory pipe is crushed flat to clear the firewall. Replacing it with our true 3.5" round mandrel-bent pipe lowers exhaust backpressure, significantly drops EGTs under heavy towing loads, and delivers much quicker turbo spool-up.
Q: Does this downpipe require custom tuning?
A: No. If installed on an otherwise stock truck, no custom tuning is required and it will not throw a Check Engine Light (CEL) or trigger limp mode because it does not alter any emissions sensors.
Q: I want to add an aftermarket EGT gauge — does this pipe have a bung?
A: No. The pipe has no pre-welded sensor bungs. The L5P factory EGT sensors are on the exhaust manifold and inside the close-coupled DPF unit. If you want a probe for an aftermarket gauge, have a shop weld a 1/8" NPT bung on the downpipe or delete pipe.
Q: Besides this downpipe, what other modifications can maximize my L5P's performance?
A: This 3.5" downpipe fixes the turbo bottleneck, but it’s just step one. To fully unlock truck’s raw power and fuel economy, upgrade to L5P Bundle all-in-one kit. This premium mega-pack bundles this exact modules to eliminate engine-choking soot in one shot!
