As someone who resides in California you would hope that this state would follows the others. But somehow California will likely find a need to test the emissions of the lithium battery in a Nissan Leaf.
Emissions testing of passenger vehicles will end on December 31, 2019 in Washington state. It ends on April 1st in Ontario. Emissions testing was no longer required in 26 North Carolina counties starting December 1, 2018. British Colombia's "AirCare" passenger vehicle testing ended in 2014. Alaska ended emissions testing in 2012.

There are multiple uplifting stories here. Air quality has improved! Fewer vehicles fail emissions testing! Government programs that have outlived their usefulness are eliminated! Car manufacturers design and build great vehicles! Use the money you no longer have to spend on testing fees to buy your own OBD II scan tool and check for emissions and other trouble codes whenever you want, from the comfort of your own garage!

Since 1996, cars have been required to have OBD II computers with standardized access ports. That probably marked the beginning of the end for government mandated emissions testing. The number of jurisdictions that still require emissions tests will probably continue to drop over the coming years.

Many emissions testing stations gradually stopped using dynamometers and exhaust probes and simply began plugging scan tools into OBD II ports. Why buy and maintain a bunch of expensive tools to test declining numbers of pre-1996 cars? The potential impact of a relatively small number of old cars on air pollution was statistically insignificant. Many states gradually stopped testing pre-OBD II cars.

If there were OBD II trouble codes, the check engine light on the dash should have already informed the driver long before he/she rolled into an emissions testing station. Most drivers learned ignoring a check engine light for too long can increase repair costs or the risk of being stranded. Florida, Kentucky, Michigan and Minnesota actually ended their emissions testing programs in the late '90s, a few years after OBD II was required on new cars.

Some emission control systems of the '70s look a lot like parts clumsily tacked onto engines designed in the '60s. Those days are long gone. Over the years, it has become increasingly hard for parts manufacturers and RockAuto to classify Emissions parts separately from Fuel & Air parts, Ignition parts, Engine parts, Electrical parts or even performance parts. "Emissions" parts like Knock Sensors and Mass Air Flow Sensors help control emissions, but they also help optimize engine performance, fuel economy and durability. The Variable Valve Timing Sprocket (cam phaser) is definitely an engine part because the valve train will not work without it, but isn't it also an emissions part because it helps eliminate the need for an exhaust gas recirculation (EGR) valve? Catalytic Converters are one of the few remaining distinct emissions parts, but they are also part of the exhaust system. ("Exhaust & Emission" is where to find them at

Emission systems on vehicles built this century frequently are blended with other critical systems that have to work properly or the engine will not run at all. There is less need for emissions testing if a broken "emissions system" means the engine cannot even propel the car to a testing station. It is great news that better engine performance, fuel economy and emissions have frequently become complementary rather than competing vehicle design goals.

Tom Taylor,