Validity
This Executive Order approved the specified parts on on November 2, 2004.
As of Sunday, November 3rd, 2024 this Executive Order has not been overturned or superceeded.
This Executive Order approved the specified parts on on November 2, 2004.
As of Sunday, November 3rd, 2024 this Executive Order has not been overturned or superceeded.
Models | Modification |
---|---|
1991-2004 model-year 4-stroke heavy-duty diesel engines originally certified to meet a particulate matter emission standard of 0.10 g/bhp-hr or lower. This exemption includes engines originally certified to meet a non-methane hydrocarbons plus oxides of nitrogen emission standard of 2.4 or 2.5 g/bhp-hr. This exemption excludes all engines equipped with an exhaust gas recirculation system and/or an aftertreatment emission control system such as a catalytic converter or a diesel particulate filter. | This exemption is only valid provided the engines meet the following operating conditions: (1) the engine exhaust temperature is greater than or equal to 260 degrees Celsius for 40-50 percent of the typical duty cycle, (2) the NOx to PM ratio is at least 8, and (3) the engine is operated using diesel with a maximum sulfur content of 50 ppmw. |