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National Clean Diesel Campaign (NCDC)

Working Together for Cleaner Air

Johnson Matthey Retrofit Technologies

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Johnson Matthey's CEM™ Catalytic Exhaust Muffler and/or DCC™ Catalytic Converter
Original Verification Letter (PDF) (2 pp, 70K, August 2004)
Extension Verification Letter (PDF) (2 pp, 70K, January 2005)
Extension Verification Letter (PDF) (2 pp, 470K, July 2010)
Technology Engine
Model/Application
Retrofit Fuel, Max Sulfur (ppm) Reductions (%)
PM NOx HC CO
CEM™ Catalytic Exhaust Muffler and/or DCC™ Catalytic Converter Highway, heavy- duty, non-urban bus, 4-cycle, non-EGR, model year 1988 – 1997 turbocharged or naturally aspirated diesel engines 15 20 n/a 50 40
CEM™ Catalytic Exhaust Muffler and/or DCC™ Catalytic Converter Highway, heavy- duty, non-urban bus, 4-cycle, non-EGR, model year 1998 – 2003 turbocharged or naturally aspirated diesel engines 15 25 n/a 50 40
CEM™ Catalytic Exhaust Muffler and/or DCC™ Catalytic Converter Highway, heavy- duty, non-urban bus, 4-cycle, 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 15 20 n/a 50 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.

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.

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Continuously Regenerating Technology3 (CRT3) Particulate Filter
Verification Letter (PDF) (2 pp; 90K; December 23, 2008)
Technology Engine
Model/Application
Retrofit Fuel, Max Sulfur (ppm) Reductions (%)
PM NOx HC CO
Continuously Regenerating Technology3 (CRT3) Particulate Filter Highway, medium and heavy heavy-duty, 4 cycle, non-EGR, model year 1994 - 2006, turbocharged or naturally aspirated engines 15 90 n/a 93 72

The following operating criteria must be met in order for appropriately retrofitted engines to achieve the emissions reductions above:

  1. The engine exhaust temperature must be at least 240° C for approximately 40 to 50 percent of the duty cycle. As there may be variations from application to application, data-logging and a review of actual vehicle operating conditions is required to ensure CRT3 compatibility.
  2. The engine’s exhaust must produce a NOx/PM ratio of at least 8, with an optimum ratio approaching 20. JM will make an assessment of the suitability of candidate engines, based upon certification emission levels or emission test data.
  3. The engine should be well maintained and not consume lubricating oil at a rate greater than that specified by the engine manufacturer.
  4. Johnson Matthey installs a backpressure monitor and high pressure indicator light on all vehicles equipped with a CRT.
  5. The engine must be operated with a fuel that contains a sulfur content of no more than 15 parts per million (ppm).

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Advanced Catalyzed Continuously Regenerating Technology (AdvCCRT) System
Verification Letter (PDF) (2 pp; 90K; April 30, 2009)
Technology Engine
Model/Application
Retrofit Fuel, Max Sulfur (ppm) Reductions (%)
PM NOx HC CO
Advanced Catalyzed Continuously Regenerating Technology (AdvCCRT) System 4-cycle, on-highway; light-, medium-, and heavy- heavy duty diesel engines including turbo-charged or naturally aspirated, EGR and non-EGR, and originally manufactured from 2002 through 2006 model years 15 90 n/a n/a 50

The following operating criteria must be met in order for appropriately retrofitted engines to achieve the emissions reductions above:

  1. The engine may or may not have a pre-existing original equipment manufacturer oxidation catalyst.
  2. The engine must not have a pre-existing diesel particulate filter.
  3. The engine must be certified at a PM emission level of at most 0.1 grams per brake horsepower-hour (g/bhp-hr).
  4. The engine must be electronically controlled.
  5. The engine should be well maintained and not consume lubricating oil at a rate greater than that specified by the engine manufacturer.
  6. Lube oil, or other oil, should not be mixed with the fuel.
  7. The engine must be operated on diesel fuel with a sulfur content of no more than 15 parts per million by weight.
  8. For reliable regeneration, the NOx to PM ratio, based on certified emissions levels, should be 20 or higher, and the engine cycle must be at 240° Celsius for 40% of the operation time.

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Selective Catalytic Reduction Technology (SCRT)
Verification Letter (PDF) (2 pp; 550K; August 11, 2010)
Technology Engine
Model/Application
Retrofit Fuel, Max Sulfur (ppm) Reductions (%)
PM NOx HC CO
Selective Catalytic Reduction Technology (SCRT) On-highway, 4-cycle, non-EGR, 250-500 hp heavy-duty diesel engines, originally manufactured from model years 1994 through 2002 15 90 70 95 90

The following operating criteria must be met in order for appropriately retrofitted engines to achieve the aforementioned emissions reductions:

  1. Must be operated on ULSD fuel (15 ppm).
  2. Engine exhaust temperature must satisfy both of the following conditions: a) greater than 240° C for 40% of operation; and b) greater than 200° C for 65% of operation. As there may be significant variations from application to application, Johnson Matthey will review actual vehicle operating conditions and perform temperature data-logging prior to retrofitting a vehicle with their SCRT system to ensure compatibility.
  3. Engine’s exhaust must produce a NOx/PM ratio of at least 8, with an optimum approaching 20. (Johnson Matthey will assess the suitability of candidate engines, based upon the applicable emission standards or emission test data.)
  4. Each installation will be equipped with a monitoring system that displays warning light(s) visible to the operator for low urea tank level, high back pressure, high inlet temperature and system abnormalities. The monitoring system will also store diagnostic error codes related to urea tank level and system malfunctions.
  5. The vehicle shall not be equipped with a crankcase oil burning system and the engine should be well maintained and not consume lubricating oil at a rate greater than that specified by the engine manufacturer.
  6. The vehicle or equipment shall not be sold or operated in geographic areas where the urea solution may freeze (-11° C).
  7. To ensure the appropriate urea is purchased, the customer is required to maintain urea purchase receipts and refill records and make them available to Johnson Matthey upon request. Urea usage log and mileage records will be collected and analyzed by Johnson Matthey on a biannual basis.
  8. To ensure that urea is readily available, the system will only be offered to centrally fueled fleets that have or are planning to have urea refilling capability.
Selective Catalytic Reduction Technology (SCCRT)
Verification Letter (PDF) (2 pp; 650K; December 15, 2011)
Technology Engine
Model/Application
Retrofit Fuel, Max Sulfur (ppm) Reductions (%)
PM NOx HC CO
Selective Catalytic Reduction Technology (SCCRT) On-highway, 4-cycle, EGR and non-EGR, 250-500 hp heavy-duty diesel engines, originally manufactured from model years 1998 through 2006 15 90 70 90 85

The following operating criteria must be met in order for appropriately retrofitted engines to achieve the aforementioned emissions reductions:

  1. Must be operated on ULSD fuel (15 ppm).
  2. Engine exhaust temperature must be greater than 240°C for 40% of operation. As there may be significant variations from application to application, Johnson Matthey will review each vehicle’s operating conditions and perform temperature data-logging prior to retrofitting a vehicle with their SCRT system to ensure compatibility. In the event that a vehicle’s application and/or duty cycle changes, temperature data-logging must be repeated to confirm that engine exhaust temperature still meets the above criteria.
  3. Engine’s exhaust must produce a NOx/PM ratio of at least 8, with an optimum approaching 20. (Johnson Matthey will assess the suitability of candidate engines, based upon the applicable emission standards or emission test data.)
  4. The engine must not have a pre-existing original equipment manufacturer (OEM) DPF or have been retrofitted with a DPF.
  5. The engine may or may not have a pre-existing OEM or retrofitted diesel oxidation catalyst (DOC).
  6. Each installation will be equipped with a monitoring system that displays warning light(s) visible to the operator for low urea tank level, high back pressure, high inlet temperature and system abnormalities. The monitoring system will also store diagnostic error codes related to urea tank level and system malfunctions.
  7. The vehicle shall not be equipped with a crankcase oil burning system and the engine should be well maintained and not consume lubricating oil at a rate greater than that specified by the engine manufacturer.
  8. Fuel additives may not be mixed with fuel unless explicitly approved by EPA for use with this device.
  9. The SCCRT must use diesel exhaust fluid (DEF) produced, handled and transported in accordance with ISO 22241.
  10. The vehicle or equipment shall not be sold or operated in geographic areas where the DEF solution may freeze (-11°C).
  11. To ensure the appropriate urea is purchased, the customer is required to maintain urea purchase receipts and refill records and make them available to Johnson Matthey upon request. Urea usage log and mileage records will be collected and analyzed by Johnson Matthey on a biannual basis.

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