How do emissions tests work

If your license plates are expired, or will expire within the week, go to your nearest DMV office and request a movement permit. In the event you have any questions, please contact the Department of Motor Vehicles Emission Control Lab in your area.

In Las Vegas, please call In Reno, please call The vehicle will need to be driven under varying conditions for up to one week. Additionally, erasing the codes may hide problems and make it more difficult to diagnose and fix your vehicle.

DON'T take the vehicle in for a test if you have a device that monitors your driving habits plugged in to the connector below the dashboard. You must remove the device and replace it after the test. Emission stations are required to fail the vehicle if such a device is plugged in.

See also the U. What is OBD? The On Board Diagnostics system is composed of a computer that monitors the emissions system and key engine components. It can usually detect a malfunction or deterioration in these components before the driver becomes aware of the problem. The U. EPA has required auto makers to install OBD systems on all cars and light-duty trucks made since OBD systems are designed to alert the driver when a component in the engine management or emissions systems begins to deteriorate or malfunction.

Early detection of minor problems, followed by timely repair, can often prevent more costly damage to components such as the catalytic converter. How does OBD work? This light cannot be turned off until the necessary repairs are completed or the condition no longer exists. When you take your car in for diagnosis or for an annual emission inspection, the repair technician retrieves the trouble codes from the computer using a "Scan Tool.

Under certain conditions, the dashboard light will blink or flash. This indicates a severe problem. The driver should reduce speed and seek service as soon as possible. If your vehicle is older, or, if for some reason the OBD is not ready for testing, a tailpipe emissions test will be performed. The Jiffy Lube technician will place a probe in the tailpipe that can detect emissions.

Designed to control exhaust and pollutants, the emission system can reduce the harmful gasses that escape into the air. But to perform this vital function, it has to be operating properly.

Like other vehicle systems — such as the battery and the brakes — the emission system sustains wear-and-tear with every mile you drive. So, beyond its role in the emissions test, this visual once-over can help keep you running cleanly and efficiently by catching a small problem before it becomes a major one. Those are the only two outcomes of an emissions test. Emissions testing is a necessary evil, and 31 states require it as part of vehicle ownership.

These tests are used to determine what, if any, carbon or chemical emissions your car is making as it runs. Every vehicle is manufactured with a number of federal emissions standards in mind, but after years of wear and tear, not every vehicle is going to pass these tests every time.

This is where you might run into problems, as I did. Different engines give off different emissions. In most areas, vehicles are only allowed to produce a certain type and a certain amount before they are considered unfit to drive. In years past, cars were tested with the use of a dynamometer, essentially a vehicle treadmill, before the testing equipment was hooked up to your tailpipe.

In , the testing procedure was changed. Now, technicians only had to hook up a diagnostic device to an onboard diagnostic port and voila, they could measure the emissions without all the fuss. The dynamo testing method involves taking the car to very high speeds to check its efficiency.

It can work to your advantage if you use a high quality fuel system cleaner right before you take the emissions test. Opt for one that has a potent detergent called Polyether Amine, otherwise it could take several uses of a lower quality cleaner to get the same effect from just one use of a premium cleaner. The fuel system cleaner will remove carbon buildup from key engine parts , which lessens the amount of carbon emissions produced by your vehicle.

If you are not that confident if you will pass the test then you can opt for a mock inspection. Some states in the U. S have this option where you can take a mock test to ensure everything is right about your car.

The results of the inspection will more or less give you an idea of the actual results you would get in the real test. If you fail the test you will have time to make adjustments and repairs to pass the actual test.

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