A mixer includes a baffle having a baffle inlet receiving exhaust gas from an upstream exhaust component and a baffle outlet directing exhaust gas to a downstream exhaust component. A cover provides a chamber between an internal surface of the cover and the baffle. An internal box is positioned within the chamber to cover the baffle outlet and includes a bottom wall with a peripheral wall extending about at least a portion of an outer periphery of the bottom wall. At least one deflector wall is positioned within the internal box to provide a wall surface that is spaced from the peripheral wall to define an internal flow path that diverts exhaust gas at least partially around the baffle outlet before exiting the baffle outlet. An opening is located in the peripheral wall to receive exhaust gas exiting the inlet and to direct exhaust gas into the internal flow path.