Modified Part Procedure

This page last reviewed April 30, 2019

Evaluation Procedure for non-OEM Parts Relating to Diesel Emission Control Systems on Heavy-Duty On-Road Engines

The PROCEDURE FOR APPROVING AFTERMARKET DIESEL PARTICULATE FILTERS FOR ON-ROAD HEAVY-DUTY DIESEL ENGINES (Evaluation Procedure) will be considered by the Air Resources Board (ARB) at a future hearing date to be determined.  The purpose of the Evaluation Procedure is to ensure that owners of diesel engines who need to replace their original DPF have an option other than purchasing it only from the original engine manufacturer (OEM). This evaluation ensures that the aftermarket DPF reduces PM the same as the OEM filter and is durable, as well as compatible, with various engines and applications.  The ARB does not charge a fee for Evaluation; however, all applicants should be aware that as part of the Evaluation process, it is the applicant’s responsibility to provide data which satisfies the ARB that their aftermarket DPF meets all requirements necessary to be approved. This includes but is not limited to: laboratory testing, in-use testing, annual warranty reporting and any other criteria which the ARB deems appropriate for complete evaluation of the aftermarket product.


April 30, 2019 - Mobile Source Certification and Compliance Fee Regulation: Meetings & Workshops

August 10, 2015 - Workshop

June 9, 2015 - "Revisions to the Draft Procedure for Approving Aftermarket Diesel Particulate Filters for On-Road Heavy-Duty Diesel Engines" Mail-Out ECARS 15-6

April 7, 2015 - Workshop

December 4, 2014 - Workshop