Who needs an emissions test in Utah
Utah requires emissions testing for most gasoline-powered vehicles registered in Salt Lake, Davis, Weber, and Box Elder counties. These four counties make up the Wasatch Front nonattainment area, where air quality does not consistently meet federal standards. If you register or renew registration for a vehicle in any other Utah county, you do not need an emissions test.
The state tests vehicles model year 1981 and newer. Diesel vehicles, motorcycles, and vehicles registered as antiques or classics are exempt. If you own a vehicle that runs on compressed natural gas (CNG) or liquefied petroleum gas (LPG), you also do not need to test.
New vehicles are exempt from testing for the first four model years after purchase. After that, they enter the regular testing cycle. Vehicles that fail inspection can still be registered if you obtain a waiver from the Utah Division of Air Quality, though this requires documented repair attempts and costs extra.
Key Takeaways
- Only vehicles registered in Salt Lake, Davis, Weber, and Box Elder counties need emissions testing; all other Utah counties are exempt.
- Gasoline vehicles model year 1981 and newer must test every two years, unless they are new, antique, or alternative-fuel vehicles.
- You can test at any certified emissions station in Utah, and the test costs between $20 and $30 depending on the station.
- If your vehicle fails, you have 60 days to repair it and retest at no additional charge at the same station.
- Vehicles that cannot pass even after repairs can obtain a waiver from the Division of Air Quality, which allows registration but requires proof of repair attempts.
When your vehicle needs testing
Utah runs on a two-year testing cycle. Your registration renewal notice will tell you whether your vehicle needs to test that year. The state staggers tests so that not all vehicles test in the same year—roughly half test in odd years and half in even years.
You must complete the test before your registration expires. If your registration is set to expire on June 30, you need to have passed the emissions test and renewed your registration by that date. Testing after expiration does not count toward that renewal, though you can test when ready after expiration and renew based on the new test result.
New vehicles do not test until four model years after the year of manufacture. A vehicle manufactured in 2023 does not need to test until 2027. Once a vehicle enters the testing cycle, it tests every two years for the rest of its life in Utah.
Where to get tested and what it costs
The Utah Division of Air Quality maintains a list of certified emissions testing stations on its website. Stations are scattered across the Wasatch Front counties and include independent repair shops, dealerships, and dedicated testing facilities. You can search by county or zip code to find stations near you.
A basic emissions test costs between $20 and $30. Some stations charge more if they perform additional diagnostics or repairs. The test itself takes 10 to 15 minutes and involves connecting your vehicle to a dynamometer, which measures tailpipe emissions while your engine runs under load.
You do not need an appointment at most stations, though calling ahead during busy seasons (spring and early summer) can save you a wait. Bring your vehicle registration and proof of insurance. The station will print your test result on the spot; if you pass, the result uploads to the state system within 24 hours and you can renew your registration when ready.
What happens if your vehicle fails
A failure means your vehicle's emissions exceed the state standard for one or more pollutants—usually nitrogen oxides (NOx), hydrocarbons, or carbon monoxide. The test report will specify which pollutant exceeded the limit and by how much.
You have 60 days from the test date to repair the vehicle and retest at the same station. The retest is free if you return within that window. Common repairs include replacing a faulty oxygen sensor, fixing a vacuum leak, or updating engine software. Some failures are caused by maintenance issues like a loose gas cap or overdue oil changes.
If you repair the vehicle and pass the retest within 60 days, you can renew your registration based on the passing result. If you cannot repair it in time or the vehicle fails again, you can request a waiver from the Utah Division of Air Quality. A waiver allows you to register the vehicle anyway, but you must document that you attempted repairs and spent at least $300 on repair attempts. Waivers are valid for one registration period only.
Vehicles exempt from testing
Diesel vehicles do not test in Utah, even if registered in the Wasatch Front counties. Motorcycles, mopeds, and off-road vehicles are also exempt. Vehicles registered as antiques or classics (typically 25 years or older, depending on state rules) do not test.
Alternative-fuel vehicles—those that run on CNG, LPO, or electricity—are exempt from emissions testing. This includes battery electric vehicles (BEVs) and plug-in hybrids (PHEVs), though a PHEV that can also run on gasoline may still be required to test depending on how it is registered.
If you own a vehicle that you believe should be exempt, check your registration renewal notice. It will state whether testing is required. If you disagree with the requirement, contact the Utah Division of Air Quality directly with your vehicle identification number (VIN) and registration details.
How to renew registration after passing the test
Once your vehicle passes the emissions test, the result is sent to the state system automatically. You can renew your registration online through the Utah Division of Motor Vehicles website, by mail, or in person at a local DMV office. You do not need to bring the test result—the state pulls it from the emissions database.
Online renewal is the fastest option and takes a few minutes. You will need your vehicle identification number (VIN), current registration number, and a valid payment method. Registration renewal costs vary by vehicle weight and type, but emissions testing does not add to the renewal fee.
If you renew before the test result uploads (which usually takes 24 hours), the system will reject your renewal. Wait a day after testing, then try again. If you are close to your expiration date, test early enough to allow time for the result to process.
Frequently Asked Questions
What if I move out of a testing county?
If you move from Salt Lake, Davis, Weber, or Box Elder county to another Utah county, you no longer need emissions testing. When you renew your registration at your new address, the state will remove the testing requirement. You do not need to do anything special—just renew normally and the requirement will not appear.
Can I test in a different county than where I live?
Yes. You can test at any certified station in any of the four testing counties, regardless of where your vehicle is registered. Some people test at a station near their workplace or on the way to another errand. The test result is valid statewide.
What if I buy a used vehicle that failed its last test?
A failed test result stays with the vehicle, not the owner. If you buy a used vehicle that failed, you inherit the repair obligation. You have 60 days from the original test date to repair and retest. If that window has closed, you will need to request a waiver or have the vehicle retested (which will likely fail again unless repairs were made).
Do I need to test if my registration is expired?
You cannot renew an expired registration without a passing emissions test (if your vehicle requires one). Test before expiration, or test when ready after expiration and then renew. Testing after expiration is allowed, but you cannot drive legally until you renew.
What if my vehicle is in the shop during the testing window?
Contact the Utah Division of Air Quality to request a testing extension. Extensions are granted for documented repairs, accidents, or other hardships. You will need to provide proof—a repair invoice, police report, or similar documentation. Extensions are typically 30 to 60 days.