An exhaust component for a motor vehicle with improved corrosion resistance, including a housing with outer walls that define an internal volume and one or more inner walls that divide the internal volume into an exhaust chamber and an interior chamber. The interior chamber is isolated from the exhaust chamber and the external environment. At least part of one outer wall or one inner wall is made of a diffusion surface alloyed metal sheet. The diffusion surface alloyed metal sheet comprises a secondary metal that is formed to a primary metal substrate by diffusion. The diffusion surface alloyed metal sheet includes edges that are oriented toward and exposed to the interior chamber. As a result, the primary metal substrate at the edges of the diffusion surface alloyed metal sheet is protected from exposure to corrosives such as salt spray in the external environment and urea in the exhaust chamber respectively.