Johnson Matthey Technology—CEM™ Catalytic Exhaust Muffler and/or DCC™ Catalytic Converter

This retrofit technology is included on EPA's Verified Technologies List for Clean Diesel.

• Technology specifications
• Criteria to achieve emission reductions
• Verification letters from EPA

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Technology specifications
 

CEM™ Catalytic Exhaust Muffler and/or DCC™ Catalytic Converter

Engine Model/Application	Highway, heavy- duty, non-urban bus, 4-cycle, EGR and non-EGR; model year 1988 – 1997, turbocharged or naturally aspirated diesel engines
Retrofit Fuel, Max Sulfur	15 parts per million (ppm)
Reduction in particulate matter (PM)	20%
Reduction in nitrogen oxide (NOx)	n/a
Reduction in hydrocarbons (HC)	50%
Reduction in carbon monoxide (CO)	40%

CEM™ Catalytic Exhaust Muffler and/or DCC™ Catalytic Converter

Engine Model/Application	Highway; Heavy- duty; Non-urban bus; 4-cycle; EGR and non-EGR; Model year 1998 – 2003; Turbocharged or naturally aspirated; Diesel engines
Retrofit Fuel, Max Sulfur	15 parts per million (ppm)
Reduction in particulate matter (PM)	25%
Reduction in nitrogen oxide (NOx)	n/a
Reduction in hydrocarbons (HC)	50%
Reduction in carbon monoxide (CO)	40%

CEM™ Catalytic Exhaust Muffler and/or DCC™ Catalytic Converter

Engine Model/Application	Highway; Heavy- duty; 4-cycle; Non-urban bus; EGR equipped model year 2003; EGR and non-EGR model year 2004 – 2006; Turbocharged or naturally aspirated; Diesel engines certified; Without a diesel oxidation catalyst
Retrofit Fuel, Max Sulfur	15 parts per million (ppm)
Reduction in particulate matter (PM)	20%
Reduction in nitrogen oxide (NOx)	n/a
Reduction in hydrocarbons (HC)	50%
Reduction in carbon monoxide (CO)	40%

Note: This verification applies to highway engines only.
The reductions are based on the installation of retrofits to engines that were originally produced without diesel oxidation catalysts or diesel particulate filters.

Criteria to achieve emission reductions

The following operating criteria are required to be met when retrofitting highway engines with the CEM™ or DCC™:

1. The engine must be operated on ultra-low sulfur diesel fuel (ULSD) (< 15 ppm S).
2. The engine exhaust temperature must achieve at least 150 degrees C during its duty cycle.
3. The engine should be well maintained and not consume lubricating oil at a rate greater than that specified by the engine manufacturer.
4. The vehicle may not be equipped with an oil burning system and lube oil or other oils may not be mixed with the fuel.
5. The engine must not have been originally certified or equipped with a diesel oxidation catalyst or diesel particulate filter.

Verification Letters from EPA

• Original Verification Letter (pdf) (66.3 KB, August 5, 2004)
• Extension Verification Letter (January 2005) (pdf) (67.42 KB, January 24, 2005)
• Extension Verification Letter (July 2010) (pdf) (467.6 KB, July 20, 2010)