A significant concern with combustion engine vehicles is the emissions that come out from their tailpipes. Thankfully, systems are in place to ensure exhaust gasses are as clean and harmless as possible. But how do you know when the car has an emission problem?

Automotive emission problems are apparent and easy to spot. Firstly, you’ll see warning lights illuminate on the dashboard, often accompanied by trouble codes through the onboard diagnostics. Besides that, emission problems lead to drops in performance and fuel efficiency. Lastly, you’ll also smell gas and exceptionally horrible odors when standing near your vehicle’s exhaust.

Emission problems are not to be taken lightly. So, read through this guide to understand what they are, what their symptoms look like, and what you should do when they happen.

Let’s get to it.

What Is An Emission Problem?

When your car has an automotive emission problem, that means there’s an issue with its emission control system. The system is designed to limit how many harmful gasses are released by your engine and its components into the surrounding environment.

However, an emission problem will result in your car releasing too many harmful exhaust gasses.

Here, it’s crucial to remember that the way that air enters a combustion engine is just as crucial as how it exits through the exhaust system. As such, an emission problem doesn’t just affect the emission control system or the surrounding environment.

Firstly, an emission problem also leads to performance issues affecting the engine’s output and how your car drives on the road. 

Besides that, a problematic emission control system will also cause you to fail any emissions or smog tests performed on your vehicle. Depending on where you live, that could mean hefty fines until the problem is fixed.

So, even though you can still drive your car when it has an emission problem, you probably shouldn’t be driving around town. The only destination you should have is your preferred mechanic so that they can troubleshoot and resolve the emission problem as soon as possible.

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What Are The Symptoms Of A Car With Automotive Emission Problems?

Emission problems can be pretty frustrating. Thankfully, there are plenty of signs you can look out for to identify the problem early and get it fixed before you get into any trouble.

Here are the 4 top signs that your car has an automotive emission problem:

#1 Warning Lights And Trouble Codes

Modern cars, especially late-model vehicles, have plenty of sensors monitoring their components. Those sensors will be the first to tell you that there’s a problem with the onboard emissions system by illuminating warning lights and displaying trouble codes.

At a minimum, you’ll find that the Check Engine light will appear on the dashboard. However, that light never tells the whole story.

Some cars will have a warning light that corresponds to the emission system in particular and that will illuminate or flash instead.

Alternatively, you can also find out through the onboard diagnostics using a scanner or code reader. When there’s a problem, the reader or scanner will display trouble codes indicating an emission problem.

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#2 Performance Loss

As you read earlier, an engine can only perform when both the incoming air (i.e. the air/fuel mixture) and the outgoing air (i.e. the exhaust gasses or emissions) are happening correctly.

That means an emission problem will prevent the engine from functioning as efficiently as it should. As a result, you’ll experience performance losses like lower power outputs, weaker torque, and trouble accelerating, just to name a few.

These problems happen because the emission system is not allowing exhaust gasses to flow out the engine towards the tailpipe as smoothly as possible.

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#3 Fuel Efficiency Drops

A combustion issue in the engine caused by an emission problem will also lead to a drop in fuel efficiency. For example, the engine might burn too much fuel or burn that fuel incompletely.

Those two problems cause the engine to guzzle more gas than it usually would, forcing you to spend more money than usual to keep your tank full.

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#4 Bad Smells

Last but not least, you’ll also experience bad smells when there’s an emission problem.

Remember: the emission system relates to the exhaust gasses coming out from the tailpipe. While those gasses were never pleasant, an emission system problem will cause you to smell gas and other unusually horrible smells when standing near the vehicle.

It’s not just about the odor, either. Those smells indicate that harmful gasses are being released into the atmosphere, causing environmental damage. Such gasses would never be released if the emission system was working correctly.

Read: Dealing With a Car Engine Derate

What Causes Automotive Emission Problems?

Emission problems can happen for several reasons, including the following:

• Overdue oil change: Regular oil changes are an essential car maintenance task for many good reasons. One of them is that an overdue oil change will cause the engine to experience emission problems, as the engine can no longer function efficiently.
• Worn-out spark plugs: Spark plugs are a critical part of the combustion process. When worn out or defective, they’ll undermine the combustion process and cause improper emissions through the emission system.
• Incorrect fuel/air mixture: A car’s emissions are affected by the air and fuel mixture that enters the engine. When that mixture is too rich, for example, it’ll cause dirtier emissions than usual.
• Dirty filters: Lastly, oil and air filters that get saturated with dirt can cause all sorts of problems for the engine, including emissions issues. Dirty filters can’t do their job of removing contaminants from the air and oil, which is why they’re so problematic.

Can I Drive With An Emission Problem?

Yes, you can continue driving your car even when it has an emission problem. That’s because the car engine and its other mechanical components are still functioning. In other words, no mechanical or safety issues will prevent you from driving.

However, doing so is never a good idea unless you’re driving your car to your local mechanic.

Here are 3 reasons why you shouldn’t drive around with an emission problem:

1. Fines: Firstly, having an emission problem means your car is likely spewing out more harmful and toxic gasses than it should. That’s against the law in many places and could get you fined heavily.
2. Failed tests: Secondly, if your car is due for emissions or smog tests of any kind, it’ll probably fail. That’s because a car with a problematic emission system is spewing out more toxic gasses than is legally allowed. Aside from the fines mentioned earlier, there’s also a chance that your car will be deemed not roadworthy.
3. Fuel inefficiency: Lastly, every moment you drive with an emission problem is a moment you’re wasting gas. The longer that goes on, the bigger the hole in your pocket you’re burning.

Bottom line? Drive your car to the nearest mechanic, so the emission problem is checked and fixed as quickly as possible.

Final Thoughts

This has been said, but it’s worth repeating: yes, a car can still function despite having an automotive emission problem. However, you shouldn’t overlook or let that issue continue for too long.

Instead, drive your car to the nearest mechanic you prefer and have them sort the issue out for you as soon as possible.

Doing so ensures that you don’t waste any fuel, continue releasing harmful emissions, or fail any emission tests that you might encounter.