PPE 116120405 High Flow Up-Pipes | 2004.5-2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY

Features:

• 53 percent more flow than stock up-pipes
• Designed for 2004.5–2005 Duramax LLY engines
• Direct bolt-on installation to factory manifolds
• Made from 11-gauge 304 stainless steel
• Internally sleeved bellows resist fatigue and cracks
• Handles extreme heat and pressure conditions
• Reduces turbo lag and improves spool time
• Lowers exhaust gas temperatures under load
• Strengthens a known factory failure point
• Improves exhaust efficiency and drive pressure balance
• Ideal for towing, racing, or high-load applications
• Long-lasting upgrade for stock or tuned trucks

Upgrade Your Duramax With The Flow It Deserves

If you're still running the stock up-pipes on your 2004.5–2005 LLY Duramax, you might be holding your truck back without even realizing it. The factory pipes simply weren’t built to stand up to the kind of heat and pressure that even a bone-stock diesel dishes out, let alone a tuned or working truck. That’s where the PPE High Flow Up-Pipes come in. They’re not just replacements, they’re serious upgrades built to move more exhaust, lower your temps, and help your turbo spool faster. You’ll get 53 percent more flow than OEM, which translates into better throttle response, improved towing power, and overall smoother engine performance. They bolt right onto your factory manifolds, so you don’t have to fuss with custom fab work to get real results. Whether you’re hauling heavy or just want your truck to breathe better, this is the kind of upgrade that makes a real difference. And with PPE’s proven durability, you’re investing in power you can count on for the long haul.

Built To Withstand The Heat And Deliver Performance Gains

The PPE 116120405 High Flow Up-Pipes are engineered specifically for 2004.5–2005 GM Silverado and Sierra 2500HD/3500HD models with the 6.6L Duramax LLY engine. These up-pipes are manufactured from 11-gauge 304 stainless steel, a material chosen for its excellent heat resistance and long-term strength in high-stress environments. Internally sleeved bellows give them added flexibility and crack resistance, especially in areas where thermal expansion can cause OEM parts to fail. The result is a highly durable, bolt-on component that provides a direct fit to factory exhaust manifolds without requiring custom modifications. With a 53 percent increase in exhaust flow compared to stock, these pipes reduce drive pressure, improve turbocharger performance, and help lower exhaust gas temperatures. This makes them a great upgrade not just for power gains, but also for reducing strain on your turbo and engine. Whether you're towing, tuning, or just want to reinforce a common failure point, PPE’s high flow design provides lasting reliability and real-world benefits. It's a smart solution for anyone looking to optimize their Duramax for performance and longevity.

Fits: 2004.5, 2005 GM Silverado/Sierra 2500HD/3500HD 6.6L Duramax LLY

Notes:

• Designed for 2004.5–2005 GM 6.6L Duramax LLY engines
• Replaces factory up-pipes that are prone to cracking
• Provides 53 percent more exhaust flow than OEM up-pipes
• Constructed from durable 11-gauge 304 stainless steel
• Internally sleeved bellows improve flexibility and lifespan
• Direct bolt-on fit to factory exhaust manifolds
• Helps lower exhaust gas temperatures under load
• Improves turbocharger performance and engine efficiency
• Ideal for towing, high-load use, and performance upgrades
• No cutting, welding, or fabrication required for installation