Get a new exhaust manifold to replace the old, damaged, or cracked factory component on your 2003-2004 Dodge 5.9L Cummins. Durable, high-silicon ductile iron manifolds are offered as an upgrade or stock replacement for many applications. A failed exhaust manifold often cracks, or leaks, from heat cycles, age, and other conditions. This can result in boost leaks, or exhaust leaks that can reduce engine efficiency and rob you of power. You'll find top-notch brands such as AFE, BD-Power, ATS, Dorman, and more.