Emissions tests in every state › Missouri
Missouri emissions testMissouri: Gateway Vehicle Inspection Program
Will your car pass Missouri's emissions test? For cars from 1996 on, the station plugs into your car and reads the same things Athena OBD reads, so you can know before you go.
Where
St. Louis City, St. Louis County, St. Charles, Jefferson
Which cars
1996+ gasoline; new vehicles exempt 4 years (under 40,000 miles); odd/even model years every two years
What it takes to pass
- The check engine light must work and be off, with no fault stored that turns it on.
- Cars from 2001 on: one of the car's self-tests may be unfinished.
- Cars from 1996 to 2000: up to 2 of the car's self-tests may be unfinished.
- Just reset the codes or changed the battery? The self-tests start over: drive normally for a few days, in town and on the highway, before you go.
Check your car's year
A guide, not a guarantee: stations also check things Athena OBD can't (the gas cap, paperwork), and rules change. Checked against Missouri's sources in October 2026.
Drive a BMW?
Athena OBD reads the engine codes every car shares. Our sister app, AutoLingo for BMW, goes much further on a BMW: the airbags, ABS, instrument cluster and body modules too, plus service resets, even on older E-chassis cars.
See AutoLingo for BMW