Texas Counties Requiring Emissions Testing 2025 Requirements. 1, 2025, but that doesn't mean you won't still need emissions. Seventeen counties — primarily in areas surrounding major metro areas and more highly populated communities — require emissions inspections.

Collin, kaufman, and rockwall counties are among those. Emissions testing is required in collin, dallas, denton, ellis, johnson, kaufman, parker, rockwall and tarrant counties in north texas.