Catalytic Converter Laws by State 2025

State	Catalytic Converter Requirement	Notes
Alabama	Required	Driving a car in the state is illegal if its catalytic converter and other air pollution control systems have been removed, switched off, or are not functioning correctly. Anyone who violates the law faces a $10,000 fine and a year in jail.
Alaska	Required	If the vehicle was originally equipped with one or more catalytic converters, the resulting engine-chassis configuration must be equipped with either the catalytic converter certified by EPA or CARB for that configuration or a replacement catalytic converter approved by the implementing agency;
Arizona	Required	If you don't have a catalytic converter in Arizona, you will fail the emissions test, and your car will not be registered. Under Arizona state law, you must pay a $300 fine if you drive a vehicle that hasn't been registered.
Arkansas	Required	all cars made after the 1974 model year must have a catalytic converter approved by the EPA. When you buy a used catalytic converter, you must also follow specific state laws. All cars require catalytic converters
California	Required	Most vehicles are required to be equipped with a catalytic converter. Some older vehicles and heavy duty trucks may be exempt. If you vehicle requires one (or two or three, depending on the model vehicle) it must be present, installed and functioning properly
Colorado	Required	all cars and trucks in Colorado must have a catalytic converter from the manufacturer, or a new aftermarket device that meets California's Air Resource Board emissions standards.
Connecticut	Required	Whether you purchase a vehicle from out of state or are transferring an out of state registration to Connecticut, the vehicle must undergo an emissions test before it can be registered, unless it's an exempted vehicle.
Delaware	Required	The DMV requires you to pass the emissions test for registration renewal, free of cost. The absence of a catalytic converter can certainly fail you in the emissions test.
District of Columbia	Required	Emissions inspections are required for vehicles prior to registration and every two years thereafter.
Florida	Required	Catalytic converters are required to pass emission testing
Georgia	Required	It is illegal for a vehicle owner to operate, or allow to operate, his car when the manufacturer's pollution control devices have been controlled or otherwise abated. Georgia maintains the standards promulgated by the National Emissions Standards Act.
Hawaii	Required	Every car in Hawaii must possess a catalytic converter as a mandatory requirement.
Idaho	Required	As per the Clean Air Act there are limits to what modifications can be made to a vehicle’s configuration and its emissions control equipment. The removal of emissions control equipment is considered tampering. In general, in order to pass an emissions test, the vehicle must meet all applicable emissions control equipment requirements of the engine or chassis whichever is newer
Illinois	Required	Not having catalytic converters will be an offense that comes under Class 4 felony
Indiana	Required	A motor vehicle that is at least twenty-five (25) years old is not required to have a catalytic converter installed as equipment on the motor vehicle unless a catalytic converter on the motor vehicle is required by rules adopted under IC 13-17-5.
Iowa	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
Kansas	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
Kentucky	Required	Catalytic converters may not be removed
Louisiana	Required	Requires vehicles registered in certain parishes and cities to pass a vehicle emissions test and safety inspection every two years
Maine	Required	CARB-compliant aftermarket replacement converters are required for California Emissions Certified vehicles, model years 2001 and newer, operated in the state. EPA-compliant converters may be used on vehicles from model years 2000 and older, OR all Federal/EPA-only Emissions Certified vehicles, regardless of model year
Maryland	Required	[1] If a vehicle is less than 5 model years old and has been driven less than 50,000 miles, any catalytic converter shall be replaced with OEM equipment. [2] If a vehicle is more than 5 model years old or has been driven more than 50,000 miles, an EPA-approved new after market catalytic converter designed for the vehicle may be installed on the vehicle. An approved, reconditioned (used) catalytic converter may be installed provided the catalytic converter is an original type for the vehicle and has been certified by an EPA-approved testing facility
Massachusetts	Required	The Massachusetts Vehicle Check program requires all passenger vehicles to pass an annual safety check and emissions test. The comprehensive inspection includes an examination of the car’s brakes, tires, horn, and other key safety components. Vehicles less than 15 years old with on-board diagnostic systems must pass an annual emissions inspection
Michigan	Required	Catalytic converters are required to pass emissions testing. In addition, driving without a catalytic converter can result in a fine from the Environmental Protection Agency (EPA)
Minnesota	Required	Under state and federal law, catalytic converters may not be removed and replaced with "converter replacement pipes" by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing converter replacement pipes on their own vehicles.
Mississippi	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
Missouri	Required	It is required for catalytic converters to pass emissions testing and the Environmental Protection Agency (EPA) has the power to fine people who drive without a catalytic converter.
Montana	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
Nebraska	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
Nevada	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
New Hampshire	Required	Automobiles registered in New Hampshire must pass an annual safety check as part of the state’s vehicle inspection program. In addition to the physical inspection needed for all cars, passenger vehicles under 20 years old require an on-board diagnostics test for early detection of malfunctioning emissions devices.
New Jersey	Required	Requires emissions testing every two years for vehicles model year 1996 and newer with a GVWR of 8,500 lbs or less, 5 model years old and older.
New Mexico	Required	New Mexico requires emissions testing at the time of registration for vehicles registering in Bernalillo County. All 1986 and newer motor vehicles up to 10,000 lbs GVW must pass an emission test every two years and at change of ownership. Diesel Vehicles has no required emission test
New York	Required	CARB-compliant aftermarket replacement converters are required for California Emissions Certified vehicles – model years 1993, 1994 or 1996 and newer – operated in the state. EPA-compliant converters may be used on vehicles from model years 1995, 1992 and older, OR all Federal/EPA-only Emissions Certified vehicles regardless of model year.
North Carolina	Required	Without your catalytic converter, you will fail both your NC safety inspection and your NC emissions inspection
North Dakota	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
Ohio	Required	Ohio requires emissions tests for vehicles every other year in Cuyahoga, Geauga, Lake, Lorain, Medina, Portage, and Summit counties (Cleveland Metropolitan area). Even model year vehicles must be tested during even-numbered years and odd model year vehicles must be tested during the odd-numbered years. All diesel-fueled vehicles equaling 10,000 pounds gross vehicle weight rating (GVWR) or less must be tested
Oklahoma	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
Oregon	Required	Requires emissions testing in the Portland and Medford metropolitan areas prior to registration and as a part of the registration renewal process. Diesel vehicles in the metropolitan areas of Portland and Medford with a GVWR of 8,500 lbs or less are required to undergo emissions testing, but are provided with the same exemptions provided to gasoline powered vehicles in those areas.
Pennsylvania	Required	Pennsylvania requires gasoline powered cars, vans and light-duty trucks (9,000 lbs. or less gross vehicle weight), with a model year 1975 and newer to undergo emissions inspections annually. The emissions inspection is to be completed before or with the annual safety inspection. Diesel vehicles are not tested for emissions.
Rhode Island	Required	Requires biennial emissions inspections to be conducted in conjunction with safety inspections.
South Carolina	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
South Dakota	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
Tennessee	Required	Annual emissions inspections must be passed prior to registration and registration renewal. Diesel vehicles are treated the same as gasoline powered vehicles for emission inspection purposes.
Texas	Required	Annual emissions inspections must be passed prior to registration and registration renewal. Annual emissions inspections must be passed prior to registration and registration renewal
Utah	Required	A person who renders inoperable an air pollution control device on a motor vehicle is guilty of an infraction.
Vermont	Required	Vermont’s Vehicle Emissions Inspection and Maintenance Program helps to ensure that Vermont vehicles remain clean throughout their useful lives by requiring annual testing of vehicle emissions control systems and repairs if needed.
Virginia	Required	Annual emissions inspections are required and must be passed prior to vehicle registration and registration renewal
Washington	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
West Virginia	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.
Wisconsin	Required	Emissions inspections are required for vehicles registered in Kenosha, Milwaukee, Ozaukee, Racine, Sheboygan, Washington and Waukesha counties of Wisconsin every other year at the time of license plate renewal. Vehicles more than five model years old require inspection at change of ownership and at time of registration renewal (every two years). All 2007 model year and newer diesel powered vehicles with a GVWR of up to 14,000 lbs are required to undergo emissions inspections.
Wyoming	Required	Under federal law, catalytic converters may not be removed and replaced with "converter replacement pipes' by any person. The 1990 Clean Air Act Amendments even prohibit private individuals from installing "converter replacement pipes" on their own vehicles.

Your catalytic converter is one of the most important parts of your vehicle. It plays a significant role in the emissions your car generates. Therefore, you need to think carefully about the type of catalytic converter you have because it could dictate whether your car is allowed on the road.

If your car does not meet certain emission standards, then you might be required to take your car to the repair shop. It can be expensive to replace a catalytic converter, so it is better to plan for the replacement instead of having an emergency repair. If you want your car to meet emission standards, and you want to reduce your carbon footprint, you need to pay close attention to your catalytic converter.

How Do I Determine What Type of Catalytic Converter I Need?

The best way to determine what type of catalytic converter you need is to take a look at your state regulations. In some states, you must have a CARB-compliant aftermarket replacement converter. This means that your catalytic converter may need to be labeled with a specific number, usually an EO (executive order), that indicates that your catalytic converter complies with the latest regulations.

Do All Vehicles Need To Have CARB-Compliant Catalytic Converters?

Not every vehicle needs to have a special catalytic converter; however, they tend to apply to vehicles made after a specific model year. There is some variation regarding what type of catalytic converter is needed, and it varies from place to place. Colorado and California require vehicles to have this type of catalytic converter if they are more than five years old or the warranty has already expired. Maine also requires its vehicles to have these types of catalytic converters, but they are only required for vehicles that were made after 2001. Finally, New York also requires CARB-compliant catalytic converters, but they are only required on specific vehicles that were made after the mid-90s.

How Do I Know If I Have the Right Catalytic Converter?

To make sure you have the right catalytic converter, you need to take a look at your vehicle’s Emissions Control information label. You can typically find this on the underside of the hood. If it is not there, it should be near your strut Tower or radiator support. Then, take a look at the emissions certification to make sure it meets the standard. You will typically either see ARB or CARB. If you live in an area that requires CARB, then you need to make sure you do not see ARB. If your vehicle does not have the correct catalytic converter, you may need to reach out to a mechanic who can clarify what you need.