Emissions Testing in Utah

Who Needs an Emissions Test or Smog Check

Emissions testing requirements in Utah apply only in Cache, Davis, Salt Lake, Utah and Weber counties. Vehicles under six years old must typically undergo testing every two years, while older vehicles may need annual inspections, depending on model year. Exemptions include new vehicles under a certain age, electric vehicles, motorcycles, and older model vehicles. Specific rules vary by county and model year.

How Often Tests Are Required

Testing frequency depends on county and vehicle age. In most regulated counties, vehicles less than six years old are tested biennially based on odd and even model years. After six years old, vehicles usually need annual tests up to a certain age threshold. Specific frequency depends on local schedules and registration timing.

Where Emissions Testing Is Required

Emissions testing is required only in certain counties with air quality oversight, not across Utah. Rural areas and counties outside the five regulated counties may be exempt. The requirement reflects local air quality zones and environmental priorities. Exact rules vary by region and are defined by county.

What Happens During the Test

During a standard emissions test in Utah, a technician connects to the vehicle’s OBD‑II port to check system readiness and emissions-related codes. If the vehicle lacks OBD‑II, a tailpipe test or visual inspection may be performed. Technicians also inspect emissions equipment like catalytic converters and gas cap. The test verifies proper function of emissions control systems and calculates pollutant outputs against thresholds.

Areas in Utah That Require Emissions Testing

Requirements differ across Utah to reflect air quality management and population density. Major urban areas fall under stricter rules. Listing cities with testing options illustrates where testing is available. Emissions testing locations in Utah include counties like Salt Lake, Davis, Weber, Utah and Cache, often serving major cities such as Salt Lake City (26 listings), West Valley City (10 listings), Ogden (10 listings), Logan (8 listings), Provo (6 listings), Murray (7 listings), Clearfield (5 listings), Sandy (5 listings), Bountiful (4 listings) and Cedar City (4 listings). These areas typically have higher concentrations of certified testing stations due to greater vehicle volume and air quality oversight. In contrast, rural or non-regulated counties generally do not require annual or biennial checks. Testing services may be limited or not required in those places, while registrants in regulated regions should plan ahead for testing and registration.

How the Emissions Test Works in Utah

The emissions test process generally takes around fifteen to thirty minutes. Before arriving, bring your current registration and a valid ID. At the station, the technician checks your vehicle’s OBD‑II system; if unavailable, they may perform a tailpipe reading or visual equipment check. Readiness monitors must be complete and there must be no active fault codes. Common failure reasons include an illuminated check engine light, incomplete readiness monitors or faulty emissions components. If your vehicle fails, you must repair the issue and return for a retest. The station sends results electronically to DMV for registration. Costs vary by station; some offer only testing while others may offer renewals. No specific fees are stated here.