2004.5-2005 GM 2500HD/3500HD 6.6L LLY Duramax Downpipes

If you're looking for more power, upgrading the restrictive factory downpipes on your 2004.5-2005 GM 6.6L Duramax should be a top priority. Our selection of downpipe kits offers an easy way to give your 2500HD/3500HD truck a bold exhaust note while boosting power, torque, and fuel efficiency. These kits also help lower EGTs, keeping your engine temperatures in check without sacrificing performance. Explore our full range of downpipes to find the perfect fit and sound for your tough GM truck, and start showing off your performance upgrades with confidence. Pair your high-performing downpipe with our selection of Single-Exit Exhaust or Dual-Exit Exhaust.  GM Duramax Fitments: 2004, 2005 GM 6.6L Duramax. Submodel Fitments: WT, Custom, LT, LTZ, High Country, 1LT, 2LT, Pro, SLE, SLT, AT4, Denali. Some exceptions apply, please see individual product pages for specific fitments.