The engineering behind this product’s reduced exhaust back-pressure truly stands out because it makes a tangible difference in engine performance. After hands-on testing, I noticed the High-Flow GM 6.6L Duramax Exhaust Manifold & Up-Pipe Kit by Pacific Performance Engineering delivers smoother throttle response and more power under load. The high-sil moly cast iron and stainless steel components aren’t just durable—they optimize exhaust flow, minimizing resistance and keeping the engine cooler.
Compared to full dual kits, this manifold and up-pipe combo tackles the core issue: improved exhaust efficiency without complex modifications. It’s perfect if you’re seeking noticeable gains in performance and longevity, especially in high-stress conditions. After evaluating other options, I believe this kit’s combination of materials and thoughtful design makes it a top-tier choice for the 2005 Duramax. It solves your biggest pain point—exhaust restriction—while maintaining reliability and ease of installation. Trust me, this is the upgrade your truck will thank you for!
Top Recommendation: High-Flow GM 6.6L Duramax Exhaust Manifold & Up-Pipe Kit by Pacific Performance Engineering
Why We Recommend It: This kit excels with its cast hi-sil moly iron high-flow manifold, stainless steel inner liner up-pipes, and pre-drilled EGT sensor bosses. It reduces exhaust back-pressure effectively and enhances airflow, outperforming other options like the dual exhaust kit which focuses on sound and appearance rather than core performance. It offers a direct, durable solution designed specifically for improved engine operation.
Best exhaust system 2005 duramax: Our Top 2 Picks
- High-Flow GM 6.6L Duramax Exhaust Manifold & Up-Pipe Kit by – Best for Duramax Performance Upgrades
- Truck Exhaust Kits – Shop Line Dual Exhaust System 2.5 – Best for Exhaust System Enhancement
High-Flow GM 6.6L Duramax Exhaust Manifold & Up-Pipe Kit by
- ✓ Reduces exhaust back-pressure
- ✓ High-quality cast iron build
- ✓ Easy EGT gauge installation
- ✕ Pricey compared to stock
- ✕ Slightly complex install
| Material | Cast hi-sil moly iron for exhaust manifold |
| Manifold Construction | High-flow design for reduced back-pressure |
| Up-Pipe Material | 11-gauge stainless steel with .120-inch wall thickness |
| Up-Pipe Diameter | 2 inches outside diameter |
| EGT Sensor Compatibility | Pre-drilled and tapped bosses for easy EGT gauge installation |
| Additional Features | Stainless steel inner liner bellows for improved exhaust flow |
You’re under the hood of your Duramax, trying to squeeze a bit more power and efficiency out of that beast. You loosen the old manifold bolts, feeling the heat radiate through your gloves, and then swap in this high-flow kit.
The cast hi-sil moly iron of the manifold feels solid, almost chunky in your hand, promising durability.
Once installed, you immediately notice how much freer the exhaust flows. The stainless steel inner liner bellows in the up-pipes give a satisfying, smooth sound that’s not just loud but refined.
You can tell the engine breathes easier—less back-pressure means snappier acceleration and a more responsive throttle.
The pre-drilled EGT bosses are a nice touch, making gauge installation straightforward. The 11-gauge stainless steel pipes look robust and fit perfectly without any fuss.
Plus, the 2-inch outside diameter ensures it stays tucked neatly into your existing system, avoiding extra fabrication. It’s a noticeable upgrade that doesn’t just boost performance but also enhances the truck’s overall sound and efficiency.
Driving around, you feel the difference on the highway—less strain on the turbo and smoother power delivery. The upgrade seems to make a real impact on daily driving and towing alike.
At $899.99, it’s an investment, but one that’s clear in the way your Duramax performs afterward.
Truck Exhaust Kits – Shop Line Dual Exhaust System 2.5
- ✓ Easy DIY installation
- ✓ Great sound enhancement
- ✓ Durable stainless components
- ✕ Slightly pricey
- ✕ Not ultra loud
| Pipe Diameter | 2.5 inches (mandrel bent aluminized tail pipes) |
| Muffler Type | Flow II high performance straight-through stainless steel muffler |
| Material | Stainless steel (muffler), aluminized steel (tail pipes) |
| Installation Hardware | Included, welding not required |
| Emissions Compliance | Full compliance with the Clean Air Act, retains all emissions control devices |
| Application | Designed for 2005 Duramax diesel trucks |
As soon as I bolted on this Truck Exhaust Kits – Shop Line Dual Exhaust System 2.5”, the first thing that caught my attention was how effortlessly it installed—no welding needed, just some basic hand tools and the included hardware.
The mandrel-bent aluminized tail pipes feel sturdy and look sharp, giving my Duramax a sleek, polished vibe. The flow II muffler really stands out—it’s a high-performance straight-through stainless model that delivers a deep, aggressive sound without sounding obnoxious.
The fitment was spot-on, and I appreciated how the system retained all emissions control devices, so I didn’t have to worry about any federal compliance issues. Plus, the stainless steel muffler doesn’t just sound good; it also offers excellent durability for the long haul.
Driving with this setup, I noticed a slight boost in throttle response and a more robust exhaust note. It’s not overly loud but definitely adds a satisfying growl when you get on it.
The 2.5-inch pipes provide a good balance of flow and efficiency, which is ideal for both daily driving and towing.
What I really like is how it transforms the truck’s overall feel—more powerful and aggressive without any hassle or fuss. The hardware quality feels premium, and the full kit makes it easy to upgrade without needing professional welding.
For the price, it really delivers a noticeable upgrade in sound and performance.