As you know, a good emission system has a positive effect on your car engine performance and fuel economy. So, we can say that it allows your vehicle to run better. Even though today’s modern cars have advanced emission control systems including computer controls and different oxygen sensors, you can face a serious emission system problem. When you get a failed emissions test result, you can find yourself researching the answer to the “why do cars fail emissions test” question.

Let’s talk about what is the emission test. The emissions from your vehicle should comply with some regulations which consider both your safety and the environment. The reason is that a bad emission system is responsible for many fuel pollutants which lead to chemical reactions with air. Also, emission testing procedures determine and measure the pollutants your vehicle releases. This process can take 15 to 30 minutes. 

Even though there are different reasons to fail emissions test, many mechanics can tend to associate “car didn’t pass emissions” with different malfunctions. For this reason, if you complain about bad emission, you need to know that your car wont pass emission test. In fact, being aware of what causes emission system problems is more important than the reasons to fail emission test. This is because it encourages you to make a regular schedule for your car’s maintenance and repair.

Therefore, we will answer the “why do cars fail emissions test” question in this article. In other words, this article includes what causes emissions system problems. If your car didn't pass emissions test, you would never miss reading this article.

Watch Out for Electrical Problems and Faulty Car Parts

The most instant test failure is to control whether the check engine light is on or not. The check engine light of your vehicle must be off to pass the emission test. But some electrical problems can cause it to turn on. If the engine control module and sensors are faulty, you can face a bad emissions system.

A faulty catalytic converter leads to emissions system problems. It cannot take enough carbon monoxide and transform it into carbon dioxide. If your catalytic converter accumulates trapped gases in the engine, you can be exposed to the smell of sulfur just like rotten eggs. This is actually a kind of warning of overheating engine. So, if you have a faulty catalytic converter, your vehicle will fail the emissions test.

In addition, a faulty exhaust system is a significant reason for a failed emissions test. It cannot convert toxic chemicals into less toxic fumes. For this reason, if you have a faulty exhaust system, you have to confront the smell of gasoline and even burning from the engine. As you can guess, this situation reveals a serious emissions system problem.

Another reason for the failed emissions test is closely related to an unbalanced combination of air and fuel. When it is pushed into the cylinders of your vehicle, unburned carbon gases are revealed through the exhaust system. So, this situation means that your car wont pass emissions.

Discover What Precautions You Need to Take Against Emission System Problem

If you’ve read this far, you can feel lucky. The reason is that there are useful precautions to prevent emission system problems. After you fix the above-mentioned faulty car parts, all you need to do is listen to our suggestions about how to say goodbye to a failed emissions test.

As you know, a cold air filter is quite important to preserve the engine performance of your vehicle. However, a clogged or dirty air filter leads to high levels of hydrocarbons, so it causes you to face a failed emissions test. For this reason, we advise you to change your air filter every 12,000 miles or once every twelve months.

Another significant precaution you need to take is based on a regular oil change. When you don’t make a regular schedule for the oil change of your vehicle, you have to deal with a serious emissions system problem. You need to know that clean oil includes fewer hydrocarbons and allows your engine to have a clean emissions output. So, if you make a regular oil change, you will say goodbye to a failed emissions test.

Apart from these precautions against an emission system problem, you should know that Pedal Commander has a CARB certification. CARB (California Air Resources Board) is a state agency in California that is responsible for controlling air pollution and enforcing emissions regulations. So, Pedal Commander is the most reliable and greenest throttle response controller on the market. Thus, all you need to do is buy Pedal Commander for the ultimate level of performance, acceleration, and fuel efficiency.