Vehicle Emissions / Registration
Harris County Requires an Emissions Test Before You Can Register Your Car
Because of air quality rules, Harris County vehicles must pass an annual emissions test before the owner can renew vehicle registration.
Harris County is part of the Houston-Galveston-Brazoria area. The EPA labeled this area a nonattainment zone for ozone — meaning the air has too much smog. To cut pollution, most gasoline cars must pass an emissions check every year. This rule covers vehicles between 2 and 24 model years old.
This test is not the same as a standard safety inspection. You cannot renew your registration until you pass it. If your renewal notice says 'TCEQ – EMISSIONS PRGM NON-COMPLIANCE,' call 1-888-295-0141. Use the DPS station locator to find a certified shop near you. Electric vehicles, diesel vehicles, motorcycles, and mopeds do not need the emissions test.
Source to confirm: TCEQ – Vehicle Emissions Inspections in Texas