US Patent 7503169 Exhaust purification apparatus

An exhaust purification apparatus has an engine controller with a storage device that stores information regarding when it is time for regeneration of the filter. The exhaust purification apparatus carries out a regeneration process of the filter based on the information stored in the storage device when the time for regeneration of the filter has been reached. The exhaust purification apparatus also determines whether an engine operation is taking place for the first time following replacement of the engine controller, and then forcibly carries out the regeneration process of the filter upon determining that engine operation is taking place for the first time following replacement of the engine controller.