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San Jose, CA 95112

Smog Test

Parts of Your Car That Needs To Be Checked Before Smog Test

California cares a lot about the quality of its air, and this is why the state has some of the strictest standards regarding vehicle emissions and smog tests. Under the law, nearly all new and old cars are required to clear the smog test to successfully register with the DMV, and failure to do so can result in heavy fines.

Contrary to what people tend to believe, smog tests have a lot of benefits and are one of the most important examinations that can be performed on cars. 

In addition to helping you comply with all the state’s laws and regulations, the test also helps protect the environment from many dangerous emissions that your exhaust system might be releasing. 

Unfortunately, our years of experience have shown us that up to 10% of all motor vehicles in the city fail their smog tests. 

While it is true that there are some cars which are quite old or simply have not been driven for quite some time. However, many smog tests fail because of the same common parts that develop faults. And while these issues can be resolved easily by simply maintaining or replacing these parts – many people remain unaware of this. 

Let’s take a look at the car parts that are often the culprits behind a failed smog test. 

  • Air Filters

The air filter of your car has a lot of important duties. It stops almost everything, from gravel to pollen, from entering in your car, its engine, and the interior of your car through the AC vents. As a result, they can often get extremely dirty and contaminated over the years.

If you don’t occasionally clean out your air filters, or if your filter is too old and is not working properly, there are a lot of chances that your exhaust emissions will contain more than normal levels of carbon monoxide, along with other forms of dirt, sand, and pollen which may not be getting filtered properly. 

All of this can cause you to fail your smog check. This is why it is always better to have your air filter cleaned or changed before going for a smog check.

  • Your Gas Cap

Similar to how an air filter stops dirt and pebbles from entering the engine, a gas cap protects your car by preventing dirt and debris from entering the gas tank. 

If you have had your car for quite some time now, there is a high chance that the seal in your gas cap has worn away, and this is causing your car to cause excessive emissions. 

But you do not need to worry, since you can simply purchase a new gas cap on your way down to GreenStar for your smog check and avoid failing without having to spend hundreds of dollars.

  • Spark Plugs

If it takes your car a long time to start, there is a high chance that you might fail your smog check. Because the longer it takes you to start your car, and the more you rev your engine trying to start it, the more emissions you release. 

As a result, it is always recommended that you replace your spark plugs as soon as they exceed the recommended amount of time. The worst-case scenario if you don’t; your car refuses to start and you get stranded somewhere you don’t wanna be.

  • Faulty Check Engine Light

This is one thing that nearly all top Smog Test technicians will look at. The check engine light is a very handy tool for finding out whether or not there is something wrong with your engine. 

However, at GreenStar we have often seen that while the engine of a car is in perfect shape, it is that tiny red light which is problematic. 

Luckily, if that is the case, you can get it fixed extremely easily, cheaply, and quickly as well. 

  • Defective EVAP System

The purpose of the EVAP control system is to make sure that the harmful gasses which are released by 

When your engine burns gasoline, the EVAP control system kicks in to prevent dangerous emissions from being directly released into the environment. 

The EVAP consists of many pipes and valves, and even if one of these gets damaged or broken, there are high chances that your car will be omitting harmful gasses and you will fail your smog test

This, by far, is the most expensive problem which can lead to a failed test, since identifying where the problem lies can be quite difficult and costly.

Fortunately, all of these problems can be easily identified and solved, either on your own or with the help of your mechanic. 

So if your car is due for a smog check, be sure to check all these parts before coming down to GreenStar, and receiving the best service any Smog Test station in San Jose has to offer!