448 is probably their because your air pump is siezed, 442 means that air pump flow is low (usually the two codes show up together when the pump is NG). Replace BOTH the pump AND check valve (above the exhaust manifold) or you'll ruin your new pump too. The pumps fail due to bad air pump check valves.

611 could be an evap purge valve, a previously loose or leaking gas cap OR another leak in the evap systems vacuum lines to the tank.

Until you fix the problems, the codes will keep re-occuring even when cleared.