Get a new exhaust manifold to replace the old, damaged, or cracked factory component on your 1998.5-2002 Dodge 5.9L 24V Cummins. Most exhaust manifolds available are cast in high-silicon ductile iron for increased durability. Exhaust manifolds can fail due to cracks or leaks from heat cycles, age, and other extreme conditions. These leaks can reduce power, and also hurt engine efficiency. You'll find top-notch brands such as AFE, BD-Power, ATS, Dorman, and more.