Buses and Coaches

Recycling Emission Control Equipment (DPF, DOC, SCR)

Recycling Emission Control Equipment from Diesel Buses

Transit, school bus and motor coaches powered with diesel engines built after 2007 include emission controls required to meet EPA emission requirements aimed at reducing emissions from diesel engines over time.  Engine manufacturers utilize a combination of technology to achieve these emission standards including:

  • Diesel Oxidation Catalyst (DOC)
  • Diesel Particulate Filter (DPF)
  • Selective Catalytic Reduction (SCR)

The emission control technologies listed above may contain platinum group metals (PGM) that act a catalyst that can be recycled by Red Fox Resources.


Manufacturers of transit and school bus engines include:

  • Caterpillar
  • Cummins
  • Detroit
  • Navistar
  • Volvo

Bus manufacturers in which Red Fox commonly recycles diesel emission controls include:

  • Bluebird
  • El Dorado
  • Gillig
  • MCI
  • IC Bus
  • Iveco
  • Navistar
  • NFI
  • NABI
  • Prevost
  • Thomas
  • Van Hool

Aftermarket DPFs and DOCs

Aftertreatment emission controls require replacement over the life of the engine.  As an alternative to buying a new or remanufactured component directly the OEM, there are several aftermarket DPF and DOC manufacturers that sell direct fit OEM replacement DPFs and DOCs.

Note that when a fleet installs an aftermarket DPF or DOC the part that has been replaced is generally a genuine OEM part that contains recyclable PGM material and does NOT have an associated core return requirement.  Red Fox Resources commonly recycles spent DPF and DOC cores that accumulate in shops after installing aftermarket components.

Manufacturers of aftermarket DPFs and DOCs include:

  • Donaldson
  • Durafit
  • Skyline
  • Dinex
  • Roadwarrior

Learn How Recycling Emissions Control Parts Works

Retrofit DPFs and DOCs

Due to local or state regulations many engines manufactured prior to 2007 were required to add DOCs or DPFs to the exhaust of buses.  There were many federal, state and local grant programs that provided funding for retrofit DPFs and DOCs to reduce emissions.  Many of these retrofitted engines have come to the end of their useful life and the retrofit components are available for recycling.

Red Fox commonly recycles retrofit parts from trucks made by the following manufacturers:

  • Cleaire
  • CDTi
  • Donaldson
  • Emission Solutions Worldwide (ESW)
  • HUG
  • Johnson Matthey

Values of DPFs and DOCs from diesel buses range from $0 – $700.

Learn How Recycling Emissions Control Parts Works

Natural Gas Powered Buses

As an alternative to diesel, many fleets are choosing to run transit and school buses powered by natural gas. Fleets typically are running compressed natural gas (CNG) or liquefied natural gas (LNG).  Like diesel-powered vehicles, natural gas engines are subject to meeting EPA emissions standards.

However, because natural gas engines do not produce the same emissions as diesel engines, they do not require the use of diesel oxidation catalysts or diesel particulate filters, instead they generally are equipped with exhaust systems that include three-way catalysts (TWC).

Cummins is the primary manufacturer of the natural gas engines that power CNG and LNG trucks.  Cummins offers 6.7 to 12 liters that typically include two (2) three-way catalysts in the exhaust system.

Through the life of the engine, the TWC may require replacement.  Typically, the replacement of the catalysts in natural gas engines is due to high exhaust temperatures resulting in melted or cracked catalysts.

Manufacturers of aftermarket TWCs for buses include:

  • Roadwarrior

The prices for spent three-way catalysts from natural gas engines range from between $55 – $300.

Learn How Recycling Emissions Control Parts Works

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