It’s been a year since Missouri returned vehicle emissions tests to private garages.

The new program makes it easier to find a place conducting the tests than the old one, because it’s no longer centralized in a relatively small number of diagnostic centers. In the first year, there have been more than 750,000 cars tested and 99 percent of cars that fail are being repaired, according to the Missouri Department of Natural Resources.

That’s the good news. Because the St. Louis metro area has too much ground-level ozone, or smog, the testing is now part of the state’s plan to clear the air.

But motorists are still being dogged by one quirk in the emissions test, which still taps into a car’s on-board computer to gauge how clean it is. (Only the owners of 1996 and newer vehicles have to wheel their cars into the shop for a test.) Unfortunately, the computer is difficult to reset after it’s been repaired, and therefore can’t be tested until it’s been driven for a while. A new law that took effect in August gives motorists 30 extra days after their vehicle’s registration has lapsed to reset the onboard computer.

Needless to say, some motorists may not feel like popping any champagne corks for this anniversary.