The Emissions Test Is Part of Houston's Ozone Plan

Harris is one of six counties in the Houston-Galveston-Brazoria ozone area. In July 2024, EPA moved the area from a moderate rating to a serious one under the 2015 ozone rule. TCEQ still lists car tests as one part of the area's clean-air work.

For a driver, the lasting point is simple: Harris County is still in the emissions program. Most gas vehicles that are 2 through 24 model years old need a yearly test before registration. Use the TCEQ vehicle page for the live rule. The ozone rating may change on a different clock.