In an effort to reduce air pollution, most states require drivers to have their vehicles tested to identify those that produce excessive emissions. These tests are known as smog tests.
States have different requirements when it comes to smog testing, and they vary in terms of exemptions and test intervals. For example, in California, the law requires that most vehicles that are more than six years old must be tested every two years, and gas-powered vehicles built prior to 1975 are exempt from testing. In states such as New York, tests are conducted annually.
Many vehicles fail smog tests. According to the Sacramento Bee, more than 10 percent of the 11 million California vehicles that were tested for emissions in 2015 failed. And older vehicles are more likely to fail than newer ones.
With proper preparation, you can improve your car’s chances of passing a smog test. Below are some useful steps you can take.
1. Give your car some time to warm up prior to the test. According to the experts at Smog Star Express, a California-based smog test facility, warmer engines have a better chance of passing a smog test. With this in mind, it’s a good idea to run errands before taking your car in to be tested. This will ensure that the engine is warm and primed for the test.
2. Make sure your car is up to date on all required maintenance, but avoid having this work done immediately before a smog test. Staying up to date on required maintenance will optimize your vehicle’s performance, and this may improve your chances of passing a smog test. For example, if you haven’t gotten an oil change within the recommended interval, your car’s oil may be contaminated, and this may cause you to fail your smog test.
However, it’s important to ensure that you put at least 100 to 200 miles on your car between maintenance work and a smog test.
In many cases, mechanics who are performing a 10-, 15- or 20-point check during an oil change or other maintenance work will disconnect your car’s battery to facilitate this process. Disconnecting the battery can temporarily erase your car’s memory chip, and this chip needs to be populated for your vehicle to pass a smog test. It can take 100 to 200 miles of driving for the chip to repopulate itself, so if you go into the test just after getting maintenance work done, you run the risk of taking the test with an empty chip.
3. If you’ve recently replaced or charged your battery, put 100 to 200 miles on the car before taking a smog test. Battery charging or replacement can temporarily erase your car’s memory chip. If you’ve recently charged or replaced your car’s battery, make sure to put 100 to 200 miles on the car before taking it in for a smog test so it can repopulate itself.
4. Make sure your car’s “check engine” light isn’t illuminated. Sometimes your car’s “check engine” light can illuminate for minor reasons, and it’s easy to delay taking the car in to have the problem investigated. However, if you’re taking a smog test, it’s important to know that an illuminated “check engine” light is automatic grounds for failing the test.
This light can be triggered by faulty oxygen sensor or catalytic converter, or by a gas cap that is loose, damaged or missing. This problem also can be linked to a damaged air flow sensor or worn spark plugs.
If your car’s “check engine” light is on, get the problem resolved before taking a smog test.
5. Make sure your car’s tires are inflated according to manufacturer recommendations. As part of the testing process, some states require cars to be driven on a piece of equipment known as a dynamometer. If the car’s tires are properly inflated, it can be driven with greater stability on this machine, and this can improve your odds of passing the smog test.
Use a tire gauge to check the air pressure of your car’s tires, and compare this pressure against the manufacturer recommendations in your owner’s manual. If the tires are underinflated, use a gas station’s air pump to bring the pressure up prior to taking your smog test.
6. Use a fuel additive to lower your car’s emission levels. Smog tests measure emission levels, and fuel additives have been shown to deliver compelling results in lowering emissions. These additives are usually added to the gas tank when you’re putting fuel in your car. They remove carbon deposits lodged within the engine. In so doing, they boost performance and diminish emission levels.
Using a fuel additive prior to a smog test may help lower your car’s emissions, and this could help improve your chances of passing the test.
Smog tests are a hassle, but they serve an essential function: They help reduce air pollution.
By following the recommendations listed above, you can make it much easier for your car to successfully tackle a smog test.