Apparatus and Method for Bypassing Sulfur Dioxide Around an Aftreatment Device in an Exhaust Gas Aftreatment System

A lean sulfur trap and a rich sulfur trap are arranged to prevent the passage of sulfur-containing exhaust gases through a sulfur-sensitive component of an aftertreatment system. After a determined period of operation, the lean sulfur trap and rich sulfur trap are purged in sequential operations, during which time exhaust gas flow is diverted around the sulfur-sensitive component, and then restored after purging of the traps.