Maine's Aftermarket Catalytic Converter Requirements & Used Catalytic Converter Prohibition

Frequently Asked Questions

What are the new aftermarket catalytic converter requirements?
Maine adopted standards for new aftermarket catalytic converters (AMCCs) effective June 1, 2018. After the warranty has expired for the original catalytic converter, any replacement catalytic converter must either be an original equipment manufacturer (OEM) part or a new AMCC certified by the California Air Resources Board (CARB or ARB) to meet the particular vehicle's original emission standards, also known as a CARB-certified catalytic converter.
What vehicles are subject to the new aftermarket catalytic converter requirements?
The new aftermarket catalytic converter requirements apply to all catalytic converter replacements, not covered under warranty, for model year 2001 and newer gasoline passenger cars, light-duty vehicles, and medium-duty vehicles (under 14,000 lbs GVW) certified to CARB or the United States Environmental Protection Agency (EPA) "50-state vehicle" emission standards.
Is it legal to sell or install an EPA federally certified AMCC after June 1, 2018?
The sale and installation of federally certified AMCCs on model year 2001 and newer CARB and EPA "50-state" certified vehicles is prohibited. EPA federally certified AMCCs may still be sold and installed on any 2000 model year and older vehicles or on any EPA federally certified vehicles, regardless of model year.
How do I determine the emissions certification of the vehicle?
The vehicle's emissions certification can be found on the vehicle emission control information (VECI) label located under the vehicle's hood or in the engine compartment.

The VECI will include information such as emissions certification, engine family or test group, engine displacement, OBD, model year, fuel type, and catalyst information. Sample VECI labels are shown below. Model year 2001 and newer CARB certified vehicles (Example 1) and EPA "50-state" certified vehicles are subject to the new AMCC requirements, while EPA federally certified vehicles (Example 2) are not.

Example 1 - Sample CARB Certified VECI Label
image of CARB certified VECI label

Example 2 - Sample EPA Federal Only VECI Label
image of EPA federal only VECI label
How do I determine the emissions certification of the vehicle if the VECI label is missing?
The OEM dealer should be contacted to purchase a replacement VECI label containing the correct test group or engine family information.
Is it legal to sell or install a used catalytic converter after June 1, 2018?
No. The installation of used converters will be prohibited on all vehicles in Maine effective June 1, 2018. This prohibition does not apply to the sale of used catalytic converters for scrap metal recycling purposes.
When can a new AMCC be legally installed?
A new AMCC may be installed when the vehicle's catalytic converter is beyond is its warranty period and a legitimate need for replacement has been established and documented.

Most vehicles in Maine are covered under the federal emissions warranty of 8 years or 80,000 miles up to 15 years or 150,000 miles for CARB certified hybrid, plug-in hybrid and partial zero emission vehicles (PZEV).
How is a legitimate need for AMCC replacement documented?
The installer is required to state the reason for replacement of the existing catalytic converter on the warranty card and also on the repair invoice. A legitimate need for replacement may be established through an annual vehicle inspection performed by a licensed inspection/maintenance (I/M) technician.

Non-I/M program related reasons for replacement may include damage resulting from vehicle accidents, cracked or melted substrate, exhaust leaks, or converter malfunctions. Non-I/M program related AMCC replacements must still be established and documented by the installer.
Can a missing catalytic converter on a vehicle still under the warranty period be replaced with an AMCC?
No. An OEM catalytic converter must be installed because the vehicle is still under the emissions warranty. An AMCC may only be installed on vehicles beyond the warranty period.
How can I tell if the vehicle is still under warranty?
By checking the vehicle owner's manual or warranty booklet or contacting an OEM representative. The vehicle's model year and odometer reading can then be compared to the warranty period and covered mileage.
I have determined that my vehicle requires either an OEM replacement catalytic converter or a CARB-certified AMCC. How do I determine the correct AMCC for my vehicle?
There are various sources of information for determining the correct new AMCC to install on a vehicle. AMCC manufacturers have hardcopy and electronic versions of their product application guides for both CARB and federal AMCCs. These application guides include the AMCC part number, make, model, model year, and engine displacement. CARB also maintains a website with lists of approved and exempted CARB-certified AMCCs. The CARB website is available at https://ssl.arb.ca.gov/AftermarketParts/catalysts.

These lists contain the CARB Executive Order number, AMCC part number, vehicle make, model, model year, and test group (engine family). There may be more than one certified AMCC available for your vehicle.

Before installation you should consult the manufacturer's application catalog to verify the converter model is designed to fit your specific vehicle application and that it is specifically approved for sale and use in California.

CARB-Certified AMCCs display a permanent label, stamp, or etching showing the CARB Executive Order approval number, manufacturer part number, manufactured date and proper direction for installation.
image of labeling example
What if a CARB-certified AMCC is not available for a particular vehicle model?
There may be instances where a CARB-certified AMCC is not available.  In these limited instances, the only option may be an OEM replacement part.
What if there are no CARB-certified AMCC or OEM replacement options for a particular vehicle?
This may occur where there are no longer any OEM replacement catalytic converters available (e.g., the vehicle make was discontinued), and none of the AMCC manufacturers have CARB-certified parts available. If this does occur, contact the Maine Department of Environmental Protection (DEP) for a suitable replacement option or a waiver. Any questions related to compliance with the new AMCC requirements should be directed to:

Maine Department of Environmental Protection
Bureau of Air Quality
Mobile Sources Section
17 State House Station
Augusta, Maine 04330-0017
Telephone: (207) 242-6103
Email: peter.g.carleton@maine.gov
Are installers required to fill out a warranty card or is the repair invoice sufficient documentation?
Installers are required to fill out the warranty card completely in triplicate. The original copy is given to the customer, one copy is kept by the installer, and the last copy is mailed to the AMCC manufacturer.
Can a repair shop sublet the AMCC replacement to another business?
Yes, the replacement can be sublet to another business such as a muffler shop. The sublet business is required to establish and document need for replacement even if this was done by the original repair shop.
What is the procedure for filling out the warranty card when the repair shop sublets the AMCC replacement to another business?
The warranty card must still be completed in triplicate with one copy to the customer, one copy to the installer, and one copy to the AMCC manufacturer. The repair shop would then make a fourth copy for its records. The repair shop may request the customer to sign the warranty card before the vehicle is sent to the business installing the AMCC. The repair shop also has the option of signing a warranty card after the work has been completed by the business installing the AMCC. In this case the repair shop must leave room for the customer to sign the warranty card as well.
How long must the installer retain a copy of the completed warranty card and installation records?
Installers are required to retain a copy of the completed warranty card and installation records for a minimum of 4 years from the date the new AMCC was installed. Records must be available for compliance review.
What is covered by the emissions warranty?
All CARB-certified AMCCs are warranted for 5 years or 50,000 miles (whichever occurs first) from defects in workmanship or materials. The warranty covers loss of conversion efficiency, OBD system malfunctions, converter shell and pipe corrosion, and faulty welds that may occur during normal usage. The warranty does not provide coverage for defects due to over-fueling, engine misfire, or physical damage caused by road debris or accidents.

Performance Standard EPA Federally Certified AMCC CARB-certified AMCC OEM Part
Emissions HC/CO/NOx reductions of 70%/70%/30% Maintains the vehicle’s original certification level (e.g., TLEV, LEV, ULEV, etc.)
Is OBDII-compatible
Maintains the vehicle’s original certification level (e.g., TLEV, LEV, ULEV, etc.)
Is OBDII-compatible
Warranty – emissions 5 years/25,000 5 years/50,000 miles 1 year/12,000 miles
Who is responsible if a noncertified AMCC is sold or installed after June 1, 2018?
The regulation states "It is unlawful for any person to install, sell, offer for sale, or advertise ..." which would enable the DEP to pursue enforcement against any person responsible for the sale and/or installation of the noncertified AMCC.

To allow time for the DEP and catalytic converter manufacturers and suppliers to conduct outreach and education regarding these new requirements; the DEP will exercise enforcement discretion for the installation of new AMCCs until January 2019, but will enforce the prohibition of used catalytic converters effective June 1, 2018.
As a vehicle owner, what are my options if my vehicle's catalytic converter needs to be replaced after June 1, 2018?
For 2001 and newer CARB and EPA "50-state" certified vehicles, all catalytic converter replacements should be either an original equipment manufacturer (OEM) replacement part or a CARB-certified new aftermarket catalytic converter. Federally certified new aftermarket catalytic converters may still be used on vehicles with a federal certification or on 2000 model year and older vehicles. Used, salvaged, or recycled catalytic converters cannot be installed after June 1, 2018 on any vehicle.