Texas counties that require smog checks number seventeen, all clustered around Houston, Dallas–Fort Worth, Austin, and El Paso. If your vehicle is registered in one of them, you need a passing emissions inspection every year before you can renew your registration.1Department of Public Safety. Inspection Items for the Annual Inspection Everywhere else in the state, there is no inspection requirement at all for a non-commercial vehicle.
One thing to clear up first. Texas ended annual safety inspections for passenger vehicles on January 1, 2025, so the old brakes-and-lights check is gone statewide.2Department of Public Safety. Vehicle Safety Inspection Changes Take Effect January 2025 Emissions testing is the only inspection a passenger car or truck still has to pass, and only in the counties below.
The Seventeen Counties
The program is run by the Texas Department of Public Safety, with air quality standards set by the Texas Commission on Environmental Quality.3Texas Commission on Environmental Quality. Vehicle Emissions Inspections in Texas Counties are grouped into four program areas:
- Houston–Galveston–Brazoria: Brazoria, Fort Bend, Galveston, Harris, and Montgomery
- Dallas–Fort Worth: Collin, Dallas, Denton, Ellis, Johnson, Kaufman, Parker, Rockwall, and Tarrant
- Austin: Travis and Williamson
- El Paso: El Paso
Registration is what counts, not where you drive. If your vehicle is registered in one of these counties, you need a passing emissions test to renew, even if the car spends most of its time elsewhere. DPS recognizes limited exceptions for vehicles permanently operated outside the affected county, such as a fleet truck based at a rural branch or an RV kept at a hunting property.4Department of Public Safety. Vehicle Emissions Testing Exemptions
If your county is not on the list, you have nothing to do beyond renewing your registration.
Which Vehicles Actually Get Tested
Being in a program county is not the whole story. The emissions program only applies to gasoline-powered vehicles between two and twenty-four model years old. A brand-new car gets its first test at its second anniversary, and anything older than twenty-four model years ages out.5United States Environmental Protection Agency. Texas SIP 30 TAC 114.50 Vehicle Emissions Inspection Requirements
Several vehicle types are exempt regardless of age:
- Diesel vehicles
- Motorcycles and mopeds
- Electric vehicles
- Military tactical vehicles
- Vehicles registered with antique plates through TxDMV
What the Test Involves
For 1996 and newer vehicles, the test is an On-Board Diagnostic (OBDII) scan. A technician plugs a scan tool into your vehicle’s computer port and reads any stored diagnostic trouble codes.6Department of Public Safety. Emissions Testing If your check engine light is on, expect to fail. That light usually means the computer has already flagged an emissions problem.
Older vehicles (1995 and earlier) still within the age window get a tailpipe test. In the Dallas–Fort Worth and Houston areas that is an Accelerated Simulation Mode (ASM-2) test on a dynamometer; in Travis, Williamson, and El Paso counties it is a Two-Speed Idle (TSI) test.
Bring a government-issued photo ID and proof of Texas auto insurance. The technician will also record your VIN and odometer reading. The DPS website has a locator for certified stations.
Inspection Fees
Fees are capped by the state and depend on your county:
- Dallas–Fort Worth and Houston area counties: up to $18.50
- El Paso, Travis, and Williamson counties: up to $11.50
Some stations charge less than the cap.7Department of Public Safety. Cost of Inspection A separate $7.50 inspection program replacement fee is collected when you renew your registration, not at the station.8Department of Public Safety. Vehicle Safety Inspection Program Changes Now in Effect
If Your Vehicle Fails
A failed test means no registration renewal until you fix the problem. The station gives you a Vehicle Inspection Report (VIR) spelling out what failed, which is where repairs start.9Texas Commission on Environmental Quality. Affidavit, Waivers and Extensions, and the Vehicle Inspection Report After repairs, you get one free retest. Most problems resolve here: a bad oxygen sensor, a loose gas cap, sometimes catalytic converter work.
If the vehicle still cannot pass, two waivers exist:
- Individual Vehicle Waiver, after at least $600 in qualifying emissions-related repairs in most affected counties, or $450 in El Paso County, with the vehicle still unable to pass.10Legal Information Institute. 37 Texas Administrative Code 23.52 – Emissions Testing Waiver
- Low Mileage Waiver, for vehicles driven fewer than 5,000 miles per year, after failing both the initial test and the free retest and spending at least $100 on emissions repairs.11Department of Public Safety. Waivers and Time Extensions
Do not let your registration lapse while you work through a failure. Texas treats expired registration as its own violation, and a citation and fine can follow. If you need more time, ask DPS about a time extension before your registration expires.
Once you pass, the station transmits the result electronically to the state. You can then renew through your county tax assessor-collector’s office, by mail, or online.