Abstract
In Korea, air pollution is worse than ever and emission regulation is getting stringent to meet emission regulations in advantaged countries. The deterioration characteristics of emission according to aging vehicles are regulated, but in Korea it is very difficult in management of exhaust emission because research material or data are not systematized properly, or lack of applied new techniques. This research provided with deterioration factors for exhausted emission characteristics and the test engine an electronically controlled heavy-duty diesel engine of at least 2000 years model satisfying emission regulation.