Emissions System Problem [How to Identify Problems with Your Emissions System]

The emissions system of a vehicle is responsible for reducing and controlling the harmful pollutants that are emitted from the exhaust pipe.

This system is designed to meet the increasingly stringent emission standards set by governments to protect the environment and public health.

However, as a result of some factors, this system can develop issues that will affect its functionality. An Emissions System Problem refers to any issue that affects the proper functioning of a vehicle’s emissions system, which is responsible for reducing the harmful pollutants emitted by the vehicle.

In this blog post, we will help you understand the emission system, its problems, and how to identify the issues.

Emissions System Problem

What is an Emission System?

Your vehicle is equipped with a system of parts known as an emission system that regulates the toxins and pollutants released from the exhaust pipe. The system consists of sensors, digital engine controls, and exhaust components. This system helps to reduce harmful gases like nitrogen oxides, carbon monoxide, and unburned hydrocarbons. 

The emissions system is a relatively complex system consisting of several components that work together to prevent poisonous gases from escaping from your vehicle. These parts include: 

  • Evaporative emissions control (EVAP) system 
  • Exhaust gas recirculation (EGR) system 
  • Positive crankcase ventilation (PCV) system
  • System of air injection
  • The catalytic converter
  • Pipe exhaust

Common Signs of Emission Control System Problem

1. Damaged Catalytic Converter

A broken catalytic converter is one of the major causes of emissions system problems. When the converter is broken, there won’t be enough carbon monoxide to be converted to carbon dioxide. 

The catalytic converter is perhaps the most well-known component of the emissions system. It uses a chemical reaction to convert harmful pollutants such as carbon monoxide, nitrogen oxides, and hydrocarbons into less harmful gases like carbon dioxide, nitrogen, and water vapor.

If your catalytic converter captures trapped gases in the motor, you may notice a sulfur smell that is comparable to that of rotten eggs. In reality, this is a caution sign for an overheating engine. Consequently, your vehicle will fail the emissions test if your catalytic converter isn’t working properly.

2. Faulty Exhaust System

A bad exhaust system is a common emission system problem. When this system is faulty, it is unable to transform hazardous substances into less hazardous fumes. Due to this, you may experience burning engine fumes as well as the odor of gasoline. This is another emission problem that will need to be fixed or replaced as soon as possible. 

Clogs, leakage, or a broken oxygen or mass airflow gauge are common exhaust system issues. You might also experience poor motor efficiency, and if your exhaust manifold is leaking, your vehicle will overheat.

3. Failed Emission Test

When your car fails to pass the emission test, it simply shows that there is something wrong with the system. There may be an issue with one or more of the emissions systems. It might be because a clogged catalytic converter isn’t effectively filtering out harmful gases. If your EGR valve is malfunctioning and not opening, your engine may be producing more nitrogen oxide gases as a result. 

4. Gasoline Odor

This is a dangerous sign of a faulty emission control system. Before being released into the environment, carbon monoxide and other dangerous gases from vehicle emissions are treated to make them safer. However, when you start perceiving gasoline inside or outside the car, it simply shows you have an emissions issue.

5. Poor Gas Mileage

Your car’s emissions control and exhaust systems have a big impact on how efficiently the car uses fuel. Assume a component, such as the fuel tank, carburettor, catalytic converter, muffler, or exhaust manifolds, has an exhaust leak or an emissions problem. 

In any of these situations, you might observe a significant decrease in fuel efficiency. It’s necessary to get a professional who can identify the cause of your decreased gas mileage because a variety of automotive problems can bring MPG loss.

6. Check Engine Light Comes On

The check engine light is the most frequent sign that an emissions problem might exist. Modern vehicles typically have very sophisticated sensors, and when there may be an emissions problem, you typically get an even more specific message.

Your exhaust system may experience problems, just two of which are a failing catalytic converter and an exhaust leak. One of your oxygen sensors may simply be malfunctioning. 

Normally, you wouldn’t want to take any chances when the check engine or any other warning light on your car illuminates. Allow Fox Run Auto to perform diagnostics and a thorough inspection to determine the precise problem.

How Can You Identify an Emissions System Problem?

Examine the positive crankcase ventilation system’s valves and cables to determine whether they need to be fixed or require maintenance. Check your evaporative emissions control system to see if any hoses, fittings, or containers require removal and replacement. 

The exhaust gas recirculation system’s hoses, valves, and pipes should all be examined for any obvious indications of damage. Verify the air injection system to make sure it is supplying your pollution system with enough fresh air. Also, examine the catalytic converter to find out if it needs to be fixed.


What are the Causes of the Emission System Problem?

  • Old Motor Oil
  • Too Much Fuel in the Air/Fuel Mixture
  • Problems With the Spark Plugs
  • Gas Cap Is Too Loose
  • Air Filter Is Dirty

Can I Drive with a Broken Emission System?

Your motor may suffer and your fuel efficiency will drop if you drive with a broken emission system. Your vehicle might also fail an emissions test as a result. So, have your car checked out by a mechanic if you think there’s a problem with the emission system.

Read: ECT Power


The emission system of your car is an important component that helps to regulate the release of hazardous substances from the exhaust pipe.

One of the most common problems with this device is a broken oxygen sensor and if there isn’t enough oxygen, the motor won’t burn the gasoline effectively. As a result, your vehicle might produce more pollution than it should. 

Another common problem is a clogged catalyst converter. This converter aids in the conversion of harmful fumes into secure ones. If your car becomes obstructed and unable to operate, it will emit more harmful pollutants. 

Driving with a malfunctioning emission system can harm your motor and reduce your fuel efficiency. Therefore, it’s essential to have your emission system fixed as soon as possible if you’re experiencing any of these issues.