2004 to 2005 Duramax engines have a lot going for them in terms of power, but that doesn’t mean you can’t make small changes to maximize performance. Duramax LLY exhaust parts can help your engine use fuel more efficiently and even give you some extra horsepower for your effort. If you know that your truck isn’t operating at peak efficiency, this can feel frustrating. Don’t let yourself settle for what you drove off the sale lot with. Check out some of these Duramax LLY exhaust parts to find what you need for optimal performance in your own truck. This kind of upgrade can make a world of difference regarding your truck’s longevity and performance.