Common Reasons Your Car Smells Like Exhaust - Service Research from Carr Chevrolet

An exhaust smell in your car is more than just unpleasant -- it's unhealthy. You don't want to be breathing in your vehicle's exhaust gasses, as they contain harmful compounds. So, if you smell an unpleasant odor in the cabin, that's something that you'll want to have addressed right away!

At Carr Chevrolet, our technicians can diagnose problems with your vehicle's exhaust. When you visit our service center, we'll consult you about what you smelled and when the problem started, so we can begin diagnosing the issue. Depending on exactly what you smelled, you may be able to help our technicians locate the problem even quicker! Here are three potential reasons that you're smelling exhaust inside your car, and the various odors you might smell in the cabin.

This Chevy vehicle's tailpipe has been embossed with the iconic Chevrolet bow-tie logo.

3. Failing Catalytic Converter (Sulfur Smell)

The catalytic converter is part of your vehicle's anti-pollution system, and in fact is legally required in most US states. Removing the catalytic converter from your car is, in fact, illegal. It's designed to convert the harmful compounds in your vehicle's exhaust fumes into less-harmful ones before they leave the tailpipe.

Over time, the catalytic converter can become overheated, contaminated with gasoline in the exhaust or simply wear out. When this happens, you're likely to notice a rotten egg, sulphurous smell coming from the exhaust. You may even smell it in the cabin. You'll want to have a trained technician repair or replace the catalytic converter on your car when this happens. Otherwise, you may not pass emissions testing if your local jurisdiction has such requirements. You'll also notice reduced acceleration performance and fuel efficiency.

This vehicle is belching black smoke from its exhaust -- a tell-tale sign of a way-too-rich air/fuel ratio.

2. Rich Air/Fuel Ratio (Gasoline Smell)

You should never smell gasoline while you're driving. If you do, you might want to blame a fuel leak, but these are rather uncommon on modern cars. A more common reason to smell gasoline in the cabin is that a rich air/fuel mixture is dumping some unburned gasoline into the exhaust. Either too much fuel is being added to the engine, or not enough air is getting to the engine, and the computer is unable to compensate automatically.

Gasoline that gets into the exhaust can also cause a backfire, or damage to the catalytic converter. You'll smell that familiar, acrid aroma of a filling station. You might also see black smoke coming from the tail pipe. This is most commonly caused by things like leaking fuel injectors, a clogged engine air filter, a bad mass airflow sensor, bad throttle body or bad oxygen sensor.

A complete vehicle engine and exhaust system is on display, complete with twin mufflers.

1. Exhaust Leak (Smoke Smell)

If you begin to smell exhaust in the cabin, but it just smells vaguely musty and smoky like regular exhaust fumes, you may simply have an exhaust leak somewhere behind the catalytic converter. This could be a damaged muffler or a cracked exhaust pipe.

As you drive, exhaust that escapes the system early can make its way to the cabin, and give it an unpleasant odor. What's more, there's another sense you might use to detect an exhaust leak: your sense of hearing. Since the exhaust sound is muffled by the muffler, an exhaust leak before the muffler will cause your car to make a loud, rattling, rumbling sound as you drive. To get this problem addressed, visit the Carr Chevrolet service center. We can patch an exhaust leak or replace a leaking muffler so you car both sounds and smells like it should once again!

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  1. CARR Chevy World

    15005 SW Tualatin Valley Highway
    Beaverton, OR 97006

    • Sales: (866) 970-1590

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