How to Find and Install DPFs

This page last reviewed April 4, 2014


STEP 1: Know Your Engine Model Year and Family Name

US EPA and ARB ensures engines and vehicles meet the lowest emissions possible.  Emission standards are set for each class of vehicle or engine.  The engine design and emission standards differ by manufacturer and engine use (passenger car, off road equipment or heavy duty truck).  Manufacturers group engines and vehicles that share similar designs and are expected to have similar emission characteristics. These groups are assigned "engine family names" by the manufacturer and submitted for certification by ARB or US EPA.

A DPF is used to clean-up an older engine's emissions.  ARB verifies DPFs that reduce emissions from a specific engine family.  Before you install a DPF, you will need to know the engine model year and engine family name (EFN).

Where can I find the engine family name (EFN)?
An EFN is a string of 10-12 letters and numbers found on the engine's emission control label (ECL) which is attached to the engine.  All 1974 and newer on-road engines are required to have an ECL. If you have difficulty locating the EFN or ECL, contact the engine manufacturer or dealer.

For off-road equipment, there are no EFN's for Tier 0 engines (pre-1996) and you should review the off-road frequently asked questions link for more information if this applies to you.  For more information on where to find an off-road engine EFN, please see the DOORS User Guide.

STEP 2: Identify Technology Compatible With Your Engine 

In order to comply with the ARB regulations, each fleet owner must research potential DPFs for compatability with their engines. There are two options that can be followed to find possible DPFs:

    Option 1: Research it yourself
ARB has many tools on its webpage to assist in determining if there is a DPF available for your engine.  First go to the Currently Verified Devices webpage.  This site lists all verified diesel emission control devices available to retrofit a diesel engine.  To determine if a DPF is available for your diesel engine, review information in the right column under “Applicability.”  A brief description of the model years and vehicle type(s) can help you identify which filters may work for your engine.  Once you identify a filter that appears to match your engine’s model year and use, click on the “Product Name” on the left side of same row. This link provides the DPF “Executive Order” which specifies ARB’s conditions for use, the DPF “Parts List”, the approved “Engine Family List", and the “Swapping & Re-designation Policy.”  Next, click the column named “Engine Family List".  Look up your engine by finding the model year, then look for your engine family name on the list.  If your engine family is not listed on each filter applicable to your engine, go to the Verification Database. Read the disclaimer and accept, then enter the engine family name to verify the information.  

The verification database only has information for 1981 through 2012 heavy duty diesel engines.  It is the applicant’s responsibility to verify and confirm that the content is accurate and up-to-date.  Verifying this information through a manufacturer or its authorized installer is recommended.

    Option 2 : Get assistance from the manufacturer or its authorized installer.
Once you have a list of manufacturers that may be available for your engine (above), you need to look up a manufacturer’s authorized installer.  There are 3 lists focused on your equipment use: on-road, off-road, and transport refrigeration units (TRUs).  Click on the list that is applicable to your engine’s use.  If your engine use is different than these categories, please contact the ARB in-use diesel program staff for more assistance.  Some installers represent multiple manufacturers.

STEP 3: How Do I Select a DPF?

ARB approves the use of a DPF for specific engines and conditions.  Make sure the DPF you are considering is approved for use on your vehicle and meets the compliance requirements for the in-use regulation that regulates your diesel engine.  Each device has its own unique operating parameters.  Before you select a DPF, you need to be aware of these terms and conditions.  The DPF Executive Order (EO) lists the terms and conditions that must be met for the DPF to be installed properly and legally.  Using a manufacturer approved installer can help with the selection process, and can provide the conditions for proper installation and operation.

Conditions include, but are not limited to, engine type or use (off-road, on-road, transport refrigeration unit, auxiliary power unit, stationary and portable), size of engine (horsepower rating, liter rating, etc.), model year of the engine, fuel use (biodiesel and other additives must be specifically allowed in the EO), engine design (use of engine gas recirculation (EGR) or a diesel oxidation catalyst (DOC)), gross vehicle weight rating of the vehicle, engine exhaust temperature (for passive DPF), PM emissions of engine, and others.  In addition, each DPF EO provides a list of compatible engines by family name.  EO's are provided on the Verification Procedure webpage at the Currently Verified program links.

In addition to identification of the approved engine families, maintaining your engine is critical.  Engines must be maintained so that it remains within the original manufacturer specifications, including lube oil use and other parameters.  Your engine's condition should be used in your decision making process as to which complicance path you choose.  If you choose to use a DPF, you need to ensure your engine meets the original equipment parameters and has no worn parts.

When operating a DPF, you need to ensure the engine components and fuel used is a part of the original equipment design.  Do not add any performance enhancing aftermarket parts unless they are listed in the DPF EO. Do not add waste oil or additives to the fuel unless approved for use in the DPF EO.  If the engine starts using lube oil, PM emissions are increased and can over load the DPF beyond its designed capacity.  Click here for more information on DPF care and maintenance.

For some DPFs, it is important to maintain normal workload of an engine because it affects the engine's exhaust temperature. Certain DPFs (passive) require a minimum engine exhaust temperature in order for the trapped PM or soot to burn off (regeneration).  For passive DPF, if the exhaust does not reach a certain temperature, the device will not regenerate, then clog up, and then possibly damage the device or possibly even the engine.  It is important to operate your truck under similar conditions as when the DPF was installed to maintain the proper engine exhaust temperature.  If you change its operation, contact your installer as soon as possible to prevent DPF damage

STEP 4: Finding An Installer

As previously discussed, each device has its own unique operating parameters, which includes your engine meeting specific conditions and operating parameters.  It is important that at the time of installation, all criteria are met and the installation is done correctly to ensure good operation of your filter, to maintain your warranty, and to maintain the equipment's anti-tampering waiver.  ARB requires that a manufacturer's authorized installer install the DPF.  

Can I install the DPF myself?
Yes, provided that you are trained and authorized by the DPF manufacturer and meet the warranty and reporting requirements in California Code of Regulations, title 13, section 2707. 

Where can I find a "manufacturer's authorized installer"?
The ARB has compiled a list of each manufacturer's authorized installers of verified DPFs.  Please note that ARB does not endorse, approve, or recommend any of the companies listed herein.  Manufacturers authorize each installer/distributor.  For the most up-to-date list of providers, please contact the manufacturers directly. There are 3 lists available on ARB's website to assist you finding an installer.  Each list is focused on your equipment use: on-road, off-road, and transport refrigeration units (TRUs).  Click on the list that is applicable to your engine’s use.  If your engine use is different than these categories, please contact the ARB in-use diesel program staff of the regulation that regulates your diesel engine for more assistance.  Some installers represent multiple manufacturers. 

Installers for On-Road Applications
Installers for Off-Road Applications
Installers for Transport Refrigeration Units

STEP 5: Before Installation

ARB recommends that you contact the DPF manufacturer or their authorized installer prior to making any purchasing decisions.  On October 1, 2014, new requirements for manufacturer authorized installers were put into place.  Advisory #MSO 2013-07 talks about these requirements and what you should look out for when choosing someone to install or work on your DPF.  Make sure that the DPF you are considering is approved by ARB to reduce engine exhaust emissions.  Remember, ARB does not recommend specific devices or installers.  As with any significant investment, prudent decision making is advisable.  In May 2007, ARB issued an advisory (Mail-Out #MSC 07-15) to assist buyers on the proper selection of ARB verified DPFs.

The following information is required prior to DPF installation:

1) You must provide the installer the engine family name or emission family name (EFN) and engine model year.  The EFN is required to ensure the DPF is verified for that engine.

2) Have the engine in proper working order – the engine must be operating within its original engine specifications.  Highly worn engines often smoke more due to high oil or fuel consumption, and therefore do not meet the original engine specifications.  If an engine does not meet the manufacturer’s specifications, repairs must be completed prior to retrofitting.  Having a poorly maintained engine does not exempt you from complying with the in-use diesel regulations.

3) Ensure the engine meets the terms and conditions listed in the DPF's Executive Order.  The factors outlined in the EO are legal requirements for each DPF approval; therefore, these conditions must be met before determining if a particular device is appropriate.  To review EO's, visit the Currently Verified Devices page.

STEP 6: No Verified Filter that Works for Your Engine

After your research, if you find that no DPF is available for your diesel engine or that all available DPFs are deemed unsuitable by the DPF manufacturer or its authorized installer, you can apply for an extension to the applicable ARB in-use diesel program that regulates your engine. Please check the regulation that affects your engine for possible extensions prior to submitting a request.

Your engine could get an extended compliance deadline if there is no verified DPF for your engine family (i.e. your engine's family name is not on any verified DPF engine family list).  You can also get an extension if there is no physical space to install the verified DPF (as determined by the DPF manufacturer or its authorized installer) or if specific criteria listed in the DPF executive order (EO) cannot be met.  Examples of EO criteria that qualify include that your engine is not able to meet the minimum engine exhaust temperature requirement or has specified equipment, such as exhaust gas recirculation (EGR) that is not allowed by the EO.  All available DPFs must be evaluated and all deemed unsuitable by the DPF manufacturer or its authorized installer to continue with the extension process. 

To obtain an extension you need to apply directly to the in-use program that regulates your diesel engine.  In your application you must include:

  • Complete owner, vehicle, and engine information, such as engine model, model year, engine family name, vehicle make, vehicle model and VIN or unique identifying information.
  • A list of all verified DPF that may work for each engine. (See Identify Technology Compatible With Your Engine)  It is important that all applicable DPFs from all manufacturers are evaulated for available technology.  If you use ARB's verification database, you are responsible for the accuracy of the information.  You may want to verify your research with the DPF manufacturers or their authorized installers.  A search must be conducted for each engine for which you are requesting an extension.  Limited technology is available for older, dirtier engines.
  • You must list and enclose letters from all DPF manufacturers with filters available for your engine.  Letters from manufacturers or their authorized installers must be on company letterhead and must contain the following information: the company contact person name and contact information, the date of analysis, a list of manufacturers the authorized installer represents, a list of DPFs evaluated, your engine indentification information (model year and family name), and a statement of why a DPF is not available or feasible.  If a DPF is verified for your engine family name but does not physically fit  your vehicle or your engine does not meet the executive order criteria required such as minimum engine exhaust temperature, the manufacturer or its authorized installer must provide pictures, data, diagrams, or other alternatives considered that verify their conclusions.  Original letters and other technical documentation from all verified DPFs deemed by a manufacturer or its representative not feasible to install are essential for "No Technology Available" determinations.
  • Applying for an extension is only the first step.  ARB will evaluate your submitted documents and conclusions.  After this evaluation, a determination will be made on whether an extension will be granted or denied.  Submittal of information does not provide an automatic extension.

The following programs provide "No Technology Available" extensions.  If your in-use program is not listed below, please contact them directly for more information:

Cargo Handling
Program website: http://www.arb.ca.gov/ports/cargo/cargo.htm
Cargo Handling staff contact list: http://www.arb.ca.gov/ports/cargo/contact.htm
Extension information: Application instructions and form (under development)
Please contact staff directly prior to applying.

Off-Road Vehicle and Equipment
Program website: http://www.arb.ca.gov/msprog/ordiesel/ordiesel.htm
Email: 8666diesel@arb.ca.gov
Diesel Hotline: 1-866-634-3735
Extension information: Application instructions and form (under development)

School Bus
Program website: http://www.arb.ca.gov/msprog/onrdiesel/onrdiesel.htm
Email: 8666diesel@arb.ca.gov
Diesel Hotline: 1-866-634-3735
Extension information: http://www.arb.ca.gov/msprog/onrdiesel/documents/faqPMExtension.pdf

Transport Refrigeration Unit (TRU)
Program website: http://www.arb.ca.gov/diesel/tru/tru.htm
Email: arber@arb.ca.gov
TRU Help Line: 1-888-878-2826
Extension information: http://www.arb.ca.gov/arber/trureg/truextensions.htm

Truck and Bus
Program website: http://www.arb.ca.gov/msprog/onrdiesel/onrdiesel.htm
Email: 8666diesel@arb.ca.gov
Diesel Hotline: 1-866-634-3735
Extension information: http://www.arb.ca.gov/msprog/onrdiesel/documents/faqPMExtension.pdf

Mail your application and supporting documentation to:
Air Resources Board
Attn: Program Name/Contact
Post Office Box 2815
Sacramento, California 95812


preload