A vehicle exhaust system includes a tubular component having an inner surface and an outer surface such that the inner surface defines a primary exhaust gas flow path. The tubular component extends along a central axis from an inlet end to an outlet end. The tubular component includes at least one ridge extending at least partly along a circumference of the tubular component. The at least one ridge includes a first portion angularly extending inwardly from the tubular component, and a second portion disposed downstream of the first portion. The second portion angularly extends inwardly from the tubular component. In some cases, the second portion defines a plurality of openings extending therethrough and spaced apart from each other. In some cases, the tubular component defines a plurality of tube openings disposed downstream of the at least one ridge.