We recently talked about the top reasons your car fails its emissions test. Since there are a lot of potential reasons that this outcome can happen, here are five more reasons your car can fail an emissions test.

1. The air filter is dirty

Your car’s air filter works to prevent dirt, dust, and other debris from entering your engine. This clean air helps your engine perform normally and run efficiently.

How does a dirty air filter impact your emissions test? Since your air filter impacts how your car ‘breathes’, dirt and clogs can change your engine’s normal combustion. In other words, it may throw off test results even if there is nothing wrong with the rest of your engine.

On average, it’s recommended to change the filter every 12,000 – 15,000 miles. If you live in an area that’s dry and dusty, or if you have a hobby like offroading, you may need to change your air filter more frequently.

2. Your spark plugs are worn out or faulty

Your car’s spark plugs provide the literal ‘spark’ needed to ignite the air-fuel mixture inside your engine’s cylinder. As they’re used, they gradually wear out over time, becoming less efficient and causing incomplete combustion. This incomplete combustion, in turn, causes increased emissions that will show up on an emissions test.

The exact lifespan of a spark plug varies depending on what they’re made of. Copper-tipped spark plugs typically last up to 20,000 miles and platinum or iridium-tipped plugs sometimes last the life of the vehicle.

3. There’s a problem in the ignition system

Reasons your car can fail an emissions test also include other issues in the ignition system, such as bad plug wires or worn out or faulty ignition coils. Like spark plugs (another part of the ignition system), these issues can cause engine misfires and increased emissions that lead to that unwanted test score.

4. There’s a malfunction in the secondary air injection system

Your secondary air injection system is a system of several components that work together to reduce vehicle emissions. If one part of this system malfunctions or breaks, that can cause an increase in the pollutants in your car’s emissions. The end result? You guessed it – a failed emissions test.

5. There’s a leak in the vacuum hose

Your car’s vacuum hose is one part of the Evaporative Emission Control System (EECS). This system is designed to prevent gas vapors from escaping into the atmosphere. A leak in your vacuum hose – or a worn out gasket connecting the hose to the rest of the system – can throw off the system’s normal operation and lead to a failed emissions test.

Pass Your Emissions Test With Ease With T3 Atlanta

If your emissions test is coming up and you want to make sure that you pass on the first try, bring your car to T3 Atlanta. We can help make sure that your car is in top condition, helping you avoid troublesome error codes or unpleasant surprises on test day. Give us a call at one of our two convenient metro Atlanta locations in Smyrna and Decatur, and we’ll pen you in for an appointment!