Effective 7 April 1998, the US EPA certified urban bus retrofit/rebuild equipment submitted by Detroit Diesel Corporation (DDC). The equipment has been certified to the 0.1 g/bhp-hr particulate matter (PM) standard, applicable to all 6V-92TA MUI engine models made by DDC for model years 1979 to 1989 and equipped with mechanical unit injectors (MUI).

The equipment consists of the base engine components used on the 25% PM reduction retrofit/rebuild kit certified by DDC (2 October 1995), components from the 25% retrofit catalyst muffler kit previously certified under the program by Engine Control Systems, Ltd. (6 January 1997), and a TurboPac supercharger system supplied by Turbodyne Systems, Inc.

The 0.10 g/bhp-hr PM level has already been triggered for all engines covered by this certification. The DDC kit may be used by operators who are required to use equipment that meets the 0.10 g/bhp-hr PM level based on earlier trigger certification.

Contact: Anthony Erb, EPA, (202) 233-9259.