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Locate your state below for information about emissions testing requirements.
Locate your state below for information about emissions testing requirements.
Please fact check this information for yourself and contact your jurisdiction. We do not guarantee accuracy or legality of these guidelines in your area. Please, if you find any information to be inaccurate let us know so we can update it.
Where a smog test is required, you usually need to follow these guidelines:
The engine and PCM need to be of the same year or newer as the vehicle it is going in.
The engine needs to be of the same category (no car engines in trucks and vice versa). So you can only put a truck LS in a Land Rover.
All emissions equipment from the donor vehicle must be retained (egr if equipped, evap, PCV, O2 sensors, catalytic converters...)
No emissions or engine related OBD codes (on the LS OBD connector), no check engine light, and must be running a stock tune.
In some areas that only check for OBD II codes, people have reported that after making sure they have no codes, they programmed the LS PCM's VIN to match their Rover and went through the SMOG test station. The testing facility does not need to know that the engine was swapped.Â
Alabama
Alabama
No emissions testing!
Alaska
Alaska
No emissions testing!
Arizona
Arizona
Emissions testing is required only in Phoenix and Tucson areas. Other areas do not require testing. It is a pretty basic/standard test. The test will check for codes on the OBDII port, exhaust sniffer check, check that catalytic converters and charcoal canister are present. It should be doable with our swap kit.
More info: https://azdot.gov/mvd/services/vehicle-services/vehicle-registration/emissions
Emissions Testing Map: https://mygis.azdeq.gov/webapps/veclocator/
You may also register the car as a Collector's vehicle if you meet the requirements.
One person has reported success going through AZ smog testing. They programmed their PCM's VIN to match the Rover, ensured no codes were thrown, and went through as normal.
Arkansas
Arkansas
No emissions testing!
California
California
Unfortunately, we're not confident that our kit would pass emissions in California counties that require smog testing. Unless the vehicle you are swapping into is a pre-OBII vehicle, like a pre-1996 Discovery 1 or Range Rover Classic.
Our kit retains the original Rover transmission. In California, that might be a deal breaker for passing emissions. Because according to their guidelines, the engine and transmission are considered a "package" when it comes to emissions. Unless the vehicle is pre-OBDII.
To learn about California emissions requirements, read the official guidelines here (starting at page 45). According to the guidelines, for OBD II vehicles: All emission system configurations must be in the original emission control system configuration as the donor vehicle, including, but not limited to, the transmission, evaporative system, exhaust, and intake.
It is possible to get exemptions for bending some of these rules. There is no way to know without talking to a BAR referee. It's possible the transmission can get an exemption, but we haven't found anybody who has done it yet.
A good read: https://ls1tech.com/articles/legal-california-engine-change/
Colorado
Colorado
Colorado requires emissions testing in some counties, some counties do not. It's a mix. Denver and Boulder metro areas require it.
We have heard people having success in Colorado by changing the LS PCM VIN to match the Rover's, ensuring no codes are thrown, and going through as normal. For SMOG testing, they run a IM240 dyno test. Gas cap is pressure tested. Visual check for cats. They scan the vehicle OBD port for codes. Alternatively (if the VIN does not match) you can take the vehicle to the state referee. They will run the same tests but verify that the engine is from the same year or newer, same category (truck vs car engine).
Usually this entails a visual inspection to make sure all emissions components are present. They may scan OBD-II codes and run a tailpipe sniff test. Follow the general guidelines at the top of this page. We think it should be doable with our kit and careful choice of parts.
Connecticut
Connecticut
Vehicles 25 years old or older are exempt from smog testing. See here: https://ctemissions.com/Content/ExemptVehicles
Other vehicles require emissions testing. Follow the general guidelines at the top of this page. Connecticut requires swapping an engine with the same number of cylinders. So going from a V8 to a V8 is no problem.
The test may involve a visual inspection to make sure all emissions components are present. They may scan OBD-II codes and run a tailpipe sniff test.
Delaware
Delaware
Delaware requires emissions testing. Testing is at no cost.
We can't find a lot of information on Delaware. We assume the general guidelines at the of the page apply. Testing may involve reading OBD codes, tailpipe sniffer, and visual inspection.
Florida
Florida
No emissions testing!
Georgia
Georgia
Georgia does not require emissions testing except in 13 Atlanta counties. Emissions testing is not required for vehicles 24 years or older. More info: https://cleanairforce.com/motorists/before-you-test
Where emissions testing is required, we are not entirely sure of the details at this time.
Hawaii
Hawaii
No emissions testing!
Idaho
Idaho
No emissions testing since 2023!
Illinois
Illinois
Some zip codes are exempt from emissions testing. But in general, Illinois requires emissions testing.
We believe Illinois' smog testing is pretty basic. They may scan OBD-II codes and run a tailpipe sniff test.
Indiana
Indiana
Indiana is working to end vehicle emissions testing in Lake and Porter counties, the only areas where it is currently required. Senate Enrolled Act 103 was signed into law and directs the state to work with the U.S. Environmental Protection Agency (EPA) to eliminate the mandate by the end of 2025.
For now emissions testing is required in Lake and Porter counties. We believe Indiana's smog testing is pretty basic. They may scan OBD-II codes and run a tailpipe sniff test.
Iowa
Iowa
No emissions testing required!
Kansas
Kansas
No emissions testing!
Kentucky
Kentucky
No emissions testing!
Louisiana
Louisiana
Vehicles registered in the five-parish area around Baton Rouge consisting of Ascension, East Baton Rouge, Iberville, Livingston, and West Baton Rouge parishes are subject to emissions testing during an annual combined safety/emissions inspection.
Maine
Maine
No emissions testing required, except for Cumberland county. We believe the Cumberland county smog test are pretty basic, consisting of an OBD II scan, possible visual inspection and tailpipe sniff test.
Maryland
Maryland
Maryland does require emissions testing. We believe the tests are pretty basic. They may scan OBD-II codes, do a visual inspection, and run a tailpipe sniff test.
Massachusetts
Massachusetts
No emissions testing required for gasoline vehicles manufactured before 2011!
Michigan
Michigan
No emissions testing!
Minnesota
Minnesota
No emissions testing!
Mississippi
Mississippi
No emissions testing!
Missouri
Missouri
Emissions testing is required but only in St. Louis City, St. Louis County, St. Charles County, or Jefferson County.
In those areas, the test is pretty basic (OBD scan, tailpipe sniff test) but the ability to pass with an engine swap is unclear. Results may vary depending on the location of the testing facility.
Montana
Montana
No emissions testing!
Nebraska
Nebraska
No emissions testing!
Nevada
Nevada
Under Nevada's new law (SB 80) engine swaps are still legal but the rules are strict around modifying or circumventing emissions equipment. Make sure to follow the general guidelines at the top of this page, and keep all emissions equipment from the donor vehicle intact.
More info here: https://dmv.nv.gov/pdfforms/ec054.pdf
New Hampshire
New Hampshire
Effective January 31st 2026, no emissions testing will be required!
New Jersey
New Jersey
New Jersey requires emissions testing. Follow the general guidelines at the top of the page. The test is pretty basic, they will likely read OBD II codes and pressure test your gas tank.Â
New Mexico
New Mexico
Only vehicles 1991 and newer registered in Bernalillo County are emissions tested. If you need to pass emissions, follow the general guidelines at the top of this page. Testing will likely be pretty basic, consisting of an OBD II scan and visual inspection.
New York
New York
Vehicles 25 year or older do not require emissions testing. Newer vehicles do.
Follow the genera guidelines at the top of this page. Expect them to scan OBD for codes, and do a visual inspection.
North Carolina
North Carolina
Vehicles 20 years or older are except from emissions testing! You may need to pass a safety/visual inspection where they check that the catalytic converters are there.
More info: https://www.ncdot.gov/dmv/title-registration/emissions-safety/Pages/emissions-inspections.aspx
North Dakota
North Dakota
No emissions testing!
Ohio
Ohio
Emissions testing is required unless your vehicle is 25 years old or older.
If you need emissions testing, follow the general guidelines at the top of the document. Expect them to scan for OBD codes, and perform a visual inspections of emissions equipment.
Oklahoma
Oklahoma
No emissions testing!
Oregon
Oregon
Emissions testing is only required in Portland and Medford areas. In Medford, vehicles 20 years or older are not required to be tested. That should exempt all Discovery IIs.
Multiple people have reported success passing SMOG in Oregon with their LS swapped D2s. Reportedly the SMOG station verified that the LS emissions systems are there, and verified no codes. Visual check for catalytic converters (they reportedly kept the D2 cats). All emission sensors present, with O2 sensors before and after the cats.
Pensylvania
Pensylvania
Emissions testing is required. Although some counties are stricter than others. Follow the general guidelines at the top of this page. Expect them to check the OBD port for codes.
Rhode Island
Rhode Island
No emissions testing required for vehicles 25 years or older. Newer vehicles must pass the test. We believe they only do basic testing by reading the OBD port for codes, and possibly a visual inspection. Follow the guidelines at the top of this page for the best chance to pass.
South Carolina
South Carolina
No emissions testing!
South Dakota
South Dakota
No emissions testing!
Tennessee
Tennessee
No emissions testing as of 2022!
Texas
Texas
Emissions testing required only in certain counties, except for vehicles 25 years or older.
Testing is required in major metropolitan areas, including Brazoria, Fort Bend, Galveston, Harris and Montgomery counties; Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall and Tarrant counties; Travis and Williamson counties; and El Paso County. Bexar County will be added to the list of counties requiring emissions tests in 2026.
To pass emissions, follow the general guidelines at the top of this document.
Utah
Utah
Vehicle inspections are required in Salt Lake, Davis, Utah, Weber, and Cache counties. More info: https://dmv.utah.gov/register/inspections/
Follow the general guidelines at the top of this page for the best chance at passing emissions.
Vermont
Vermont
Emissions testing is required. Follow the general guidelines at the top of this page for the best chance at passing emissions.
Virginia
Virginia
Emissions testing is required except for vehicles 25 years or older. Only if garaged in these localities:
Counties of Arlington, Fairfax, Loudoun, Prince William or Stafford
Cities of Alexandria, Fairfax, Falls Church, Manassas or Manassas Park
More info: https://www.dmv.virginia.gov/vehicles/registration/emissions
Follow the general guidelines at the top of this page for the best chance at passing emissions.
Washington
Washington
No emissions testing!
West Virginia
West Virginia
No emissions testing!
Wisconsin
Wisconsin
Vehicles 20 years or older are exempt. That includes all Discovery IIs!
Otherwise, vehicles customarily kept in one of these seven southeastern Wisconsin counties require an emissions test: Kenosha, Milwaukee, Ozaukee, Racine, Sheboygan, Washington and Waukesha.
https://wisconsindot.gov/Pages/dmv/vehicles/rnew-plts/emissiontest.aspx
Wyoming
Wyoming
No emissions testing!
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