Vehicle Registration
Madison County vehicles skip emissions testing at inspection
Cars registered in Madison County do not need an emissions test — only a standard safety inspection is required under Texas's Two Steps, One Sticker program.
Texas runs a combined inspection and registration system called Two Steps, One Sticker. You get your vehicle inspected first, then renew your registration. In many urban Texas counties, that inspection includes an emissions (smog) test. Madison County is not on that list.
Vehicles here go through a standard safety inspection only — things like lights, brakes, tires, and wipers. Once you pass, you renew registration with the tax office. The list of counties that require emissions testing is published on the TxDMV website. If you move from a city county to Madison County, you may notice the process is simpler and often cheaper.
Source to confirm: TxDMV — Two Steps, One Sticker