REACTIVATION OF CATALYST FOR LEAN NOX TRAP

Example methods and systems for treating exhaust from an internal combustion engine may generally determine a catalytic converter in an exhaust system is at least partially deactivated by detecting an elevated exhaust temperature and a lean-burn operating condition. In response, a deactivation level of the catalytic converter may be determined, which may be compared with a threshold deactivation level. A magnitude of a temporary rich-fuel operating condition as a response may be determined based upon the comparison. The catalytic converter may be reactivated with the temporary rich-fuel operating condition.