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Catalytic Converters

A catalytic converter is an exhaust emission control device that reduces toxic gases and pollutants in exhaust gas from motor vehicle engines into less-toxic pollutants by catalyzing a redox reaction (an oxidation and a reduction reaction). Catalytic converters are used with gasoline and diesel-powered engines.

DEC has adopted California's aftermarket catalytic converter (AMCC) requirements that include:

These requirements can be found under subdivision 218-7.2(c) (leaves DEC website). NYS' AMCC requirements apply to all model year 1993 and newer on-road motor vehicles, with the exception of 1995 model year vehicles, certified by the California Air Resources Board (CARB) including vehicles with 50 state emissions certification. Use of an EPA-certified new AMCC is still permitted on federally certified (not CARB or 50 state) and pre-1993 model year vehicles. Distribution centers located in NYS may continue to supply EPA-certified AMCCs for applicable NYS vehicles and for sale outside of NYS.

Prohibition of Used Catalytic Converters

It is unlawful for any person to sell, offer for sale, advertise, or install any used, recycled, or salvaged catalytic converter on any vehicle in NYS. This prohibition, under subdivision 218-7.2(c)(2) (leaves DEC website), applies to all vehicle types and model years. A used catalytic converter is not a new AMCC or an original equipment manufacturer (OEM) replacement part. This prohibition does not apply to the sale of used catalytic converters for recycling purposes.

New AMCC Standards

Subdivision 218-7.2(c)(1) (leaves DEC website), states it is unlawful for any person to sell, offer for sale, advertise, or install any new AMCC for use on 1993, 1994, 1996 and newer CARB and 50 state certified vehicles in NYS unless that new AMCC has been certified by CARB or is an OEM replacement part.

A new AMCC is defined as being constructed of all new materials and is not an original equipment catalytic converter. New AMCCs for CARB and 50 state certified vehicles will be required to:

  • Display a permanent etching, stamp or label on the catalytic converter shell showing the CARB Executive Order approval number, the manufacturer part number, date of manufacture, and proper installation direction.
  • Comply with a vehicle's original emissions certification limits.
  • Be compatible with the onboard diagnostic systems (OBD II) on 1996 and newer vehicles.
  • Be covered by a warranty for a period of 5 years or 50,000 miles of use, whichever comes first. The warranty will cover failures related to construction defects, performance defects, and OBD II compatibility issues.

EPA certified AMCCs may still be used on EPA federally certified vehicles.

Vehicle Emissions Certification

The vehicle's emissions certification can be found on the vehicle emission control information (VECI) label located in the vehicle's engine compartment. The VECI label includes emissions certification, engine family or test group, engine displacement, OBD, model year, fuel type, and catalyst information. Sample VECI labels are shown below. The CARB certified and 50 state certified vehicles (Examples 1-3) are subject to CARB certified AMCC requirements.

Example 1 - Sample CARB Certified VECI Label

Image of CARB Certified VECI label

Examples 2 and 3 - Sample CARB/EPA 50 State VECI Labels

Images of CARB/EPA 50 State VECI labels

If the VECI cannot be located, an OEM dealer may be contacted to obtain a replacement VECI label containing the correct test group or engine family information.

AMCC Costs and Certification

The cost of new CARB AMCCs is higher, compared to a federal or noncompliant AMCC, primarily due to the increased catalyst loading required. This increased purchase price is partially offset by more robust warranty coverage.

For new AMCCs, the certification process typically takes 6-12 months to complete. CARB indicated that manufacturers can aid this process by ensuring that all required emission testing is completed and that all files submitted electronically to CARB are accurate and in the correct XML file format to be entered into CARB's searchable AMCC database.

When an AMCC can be installed

A new AMCC may be installed when the vehicle is beyond its emissions warranty period and a legitimate need for replacement has been established and documented. Most vehicles in NYS purchased prior to 2016 are covered under the federal emissions warranty of 8 years or 80,000 miles. 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.

If the vehicle is still under the emissions warranty, an OEM catalytic converter must be installed. AMCCs may only be installed on vehicles beyond the emissions warranty period. You can verify your vehicle's warranty by checking the vehicle owner's manual or warranty booklet, or by contacting an OEM dealership and providing your vehicle identification number (VIN). The vehicle's model year and odometer reading can then be compared to the warranty period and covered mileage. Warranty coverage begins on the date the vehicle was first registered.

If your vehicle requires a CARB-certified AMCC, there are several ways to determine the correct catalytic converter 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, engine family, and engine displacement. CARB also maintains a website (leaves DEC website) with lists of approved and exempted AMCC. These lists contain the CARB Executive Order number, AMCC part number, vehicle make, model, model year, and engine displacement. There may be more than one certified AMCC available for your vehicle.

There may be instances where a CARB certified AMCC is not available for a particular vehicle model. In these limited instances, the only option may be an OEM replacement part.

There may also be cases where neither a CARB certified AMCC or OEM replacement catalytic converter is available for a particular vehicle model. This would occur where there are no longer any OEM replacement catalytic converters available (e.g., the make was discontinued), and none of the AMCC manufacturers has received a CARB Executive Order. Contact DEC as there may be a suitable replacement option for a similar vehicle application.

AMCC Repair and Installation

AMCC installers are required to state the reason for replacement of the existing catalytic converter on the warranty card and also on the repair invoice. If the need for replacement was an I/M inspection failure, the installer should include a copy of the NYVIP Vehicle Inspection Receipt (VIR), repair invoice(s), and any additional documentation along with the warranty card. The vehicle owner or consumer must also sign their name on a statement indicating they understand the reasons for replacement of the catalytic converter.

Installers are required to completely fill out the warranty card 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. The repair shop may request the customer to sign the warranty card before the vehicle is sent to the business actually 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.

Installers are required to retain a copy of the completed warranty card for a minimum of 4 years from the date the new AMCC was installed.

NYS vehicle owners cannot take their vehicles to a neighboring state to have noncompliant AMCCs installed. This practice is not allowed by Part 218 and may be subject to enforcement. Noncompliant AMCCs may be less expensive, but they are not required to provide the warranty coverage of CARB-certified AMCCs. Vehicle owners may also encounter problems in being able to pass the annual NYS motor vehicle emissions inspection.

Subletting AMCC Repair and Installation

A repair shop can sublet AMCC replacement to another business, such as a muffler shop. The sublet business is required to establish and document the need for replacement even if the replacement was done by the original repair shop. If a repair shop sublets work out to another shop, the repair shop makes a fourth copy of the warranty card to keep in its records.

Emissions Warranties for AMCCs

All CARB certified AMCCs are warranted for 5 years or 50,000 miles (whichever occurs first) for performances and 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 overfueling, engine misfire, or physical damage caused by road debris or accidents.

The warranty reporting requirements in NY are identical to those required in California, with the exception of sales data. AMCC manufacturers are required to submit data for AMCCs produced for sale in NYS in their semi-annual warranty reports. NYS is not requiring AMCC manufacturers to submit quarterly quality control reports at this time.

Taxi cabs are not exempt from AMCC emission warranty reporting requirements.

Noncompliant AMCCs

It is illegal to install noncompliant AMCCs in NYS. Part 218 states "It is unlawful for any person to install, sell, offer for sale, or advertise ..." which enables DEC to pursue enforcement against any person responsible for the sale or installation of a noncompliant AMCC.

The penalty structure for violations of the AMCC standards incorporated in Part 218 are set forth in NYS Environmental Conservation Law §71-2103 and §71-2105. Violations are subject to minimum penalty of $500 for a first violation, and up to $26,000 for each subsequent violation. This penalty structure is identical to the one which is used to enforce new vehicle sales under Part 218. A violation would be for each noncompliant converter sold and/or installed. Failure to maintain complete records or submit reports may also result in a violation. DEC periodically conducts audits at facilities to ensure compliance with the requirements of Part 218.

Reporting Requirements

Manufacturers of AMCCs are required to submit semi-annual warranty information reports to DEC. The reports are identical in format and content to those submitted to California and must contain:

  • the manufacturer's name
  • a description of each class or category of California-certified new AMCCs, including:
    • model year and series
    • the cumulative number and percentage of catalytic converters covered by the CARB Executive Order
    • the number of each type of catalytic converter produced for sale.
  • The lone exception is the inclusion of NYS sales data rather than California sales.

If confirmed warranty claims for new AMCCs in NYS exceed 4% or 100 claims, whichever is greater, the manufacturer is required to submit additional information in the warranty information report. This required information includes:

  • type of failure,
  • probable cause of the failure, and
  • an evaluation of the impact on vehicle emissions.

Installers of AMCCs are required to complete a warranty card in triplicate with the original going to the customer, one copy to the installer, and one copy to the manufacturer of the converter.


DEC's enforcement of the AMCC standards for the period January 1, 2019 to December 31, 2020 has resulted in:

  • 201 AMCC audits conducted
  • 124 violations of the AMCC standards discovered
  • 13 Notices of Violation issued
  • Fines ranging from $500 to $5,000
  • $13,500 in penalties collected

Since enforcement of the AMCC standards began January 1, 2014 there have been:

  • 1,028 AMCC audits conducted
  • 458 violations of the AMCC standards discovered
  • 150 Notices of Violation issued
  • Fines ranging from $500 to $5,000
  • $100,500 in penalties collected