Car Exhaust…What’s That? Here’s Everything You Need to Know

March 11th, 2022 by

A white vehicle is shown on a lift at an exhaust shop near you.

When you think of car maintenance, what immediately comes to mind? Most people think about oil changes and tire rotations, but your search for an “exhaust shop near me” proves you’re thinking beyond the most common automotive services. Is this because your vehicle is producing more exhaust smoke than normal? Or is it because you’ve noticed odd vibrations, strange smells, or a lag in acceleration?

There are many indications that you may be experiencing problems with your exhaust system. Our certified service technicians are more than capable of making an official diagnosis and handling the repairs, but your search tells us that you’re looking for a little more information before you venture over to our service department. As experts on exhaust, we’re here to answer all your exhaust questions, from what it does and its components to signs of potential problems.

Exhaust: What It Does

At its core, the exhaust system is designed to move harmful gases away from your vehicle’s engine and cabin. As these gases pass through the system’s various components, they are broken down into less harmful gases that meet national emissions standards. The exhaust also controls the engine’s noise, thanks to components like the muffler, and improves both engine performance and fuel consumption since removing dangerous gases makes more room for the oxygen your engine needs.

A close up of a vehicle's exhaust is shown.

Exhaust System: Its Components

Phase 1: Exhaust Manifold Collects Gases

Attached to the engine, the exhaust manifold is a single piece made of either cast iron, stainless steel, or aluminum and plays a vital role in your vehicle’s exhaust system. During the combustion process, harmful gases are produced by the engine. The manifold collects the gases from each cylinder, channeling them into the rest of the exhaust system.

As the manifold collects the gases, it constantly monitors the oxygen levels using a mounted oxygen sensor. The sensor measures how much oxygen is in the exhaust at any given moment. Based on the measurements, the car’s computers will add or subtract fuel as needed to optimize the engine’s performance and improve efficiency.

Phase 2: Catalytic Converter Ensures Cleanliness

The catalytic converter is vital to your vehicle’s exhaust system. The converter does exactly as its name implies––it converts dangerous gases into carbon dioxide and water vapor. This prevents toxic pollutants like carbon monoxide and hydrocarbons from escaping into the atmosphere. The catalytic converter is a key component in your vehicle’s emissions control systems.

Phase 3: Mufflers Control Noise

As gases continue through the exhaust system, they pass through a muffler. Mufflers are made of baffles that dampen the noise from the engine, gases, and the combustion process. If you’ve ever heard an obnoxiously loud vehicle, it’s likely a faulty muffler that is failing to insulate the sound of the engine.

Phase 4: Exhaust Pipe Vents Gases

Once the muffler quiets the gases, the less hazardous gases reach the final phase of the exhaust system. They move through the exhaust pipe or tailpipe. Often made of stainless steel tubing, the exhaust pipe vents the gases out and away from the engine and cabin.

A mechanic is shown inspecting a rusty exhaust.

Exhaust Issues: Common Symptoms and Problems

Check Engine Light

A check engine light can mean a lot of things, including a faulty exhaust. When the light comes on, bring your vehicle to our service department, where our certified technicians can diagnose the issue. It could be something as minor as a faulty gas cap or an exhaust issue that’s led to slow acceleration and reduced efficiency.

Strange Smells

Do you smell exhaust inside the cabin or something burning? A strange smell can indicate that there’s an exhaust leak or a broken pipe in the system that’s leaking gas into your car. This can be extremely dangerous and requires immediate attention. If you smell something burning, this could be from parts and wiring actually burning in the engine. This is sometimes caused by the extreme heat that emanates from the exhaust gases released by a leak or broken component.

Black, Blue, or Gray Smoke

Is the smoke coming from your exhaust pipe a strange color? One of the most common indicators of a problem with your exhaust is an abnormal amount of smoke that’s either black, blue, or gray in color. The color of the smoke indicates the underlying problem. For example, water vapor comes out like thin white smoke, which is completely normal.

Blue or gray exhaust smoke, however, indicates that your engine is burning oil due to an oil leak. Our technician might ask if you’ve noticed blue smoke when you accelerate, as this indicates an issue with the piston rings. If you see blue smoke when slowing down, it could be an issue with the valve guides on the cylinder heads. Black smoke is another cause for concern and indicates that your vehicle is burning too much fuel, which is often caused by a blocked manifold.

Visible Rust or Broken Parts

If you don’t see or smell anything, look at the exhaust pipe itself and see if it’s hanging loose or dragging on the ground. Your exhaust pipe shouldn’t hang or drag, which means a component is loose or broken and needs immediate repair. You’ll also want to keep an eye out for rust, which is detrimental and extremely dangerous on any part of your vehicle.

If you don’t spend a lot of time behind the wheel and make a lot of short trips, this can increase the likelihood of your exhaust system rusting. It takes time for your exhaust system to heat up enough to evaporate the water droplets from the catalytic converter. Shorter trips don’t give the system enough time to get hot, leaving the water to collect in one place. Over time, this results in corrosion.

Sudden Decrease in Fuel Economy

Most drivers have a good idea of how far they can go on a full tank of gas. When your trips to the gas station start becoming more frequent, it’s time to have the exhaust system checked. A faulty exhaust system can force the engine to work harder and use more fuel. A sudden decrease in fuel economy can also be the result of faulty sensors in the exhaust system given the car’s computers inaccurate readings.

Proactive Maintenance Is Key

Until now, have you ever given your exhaust system a second thought? You’re not alone. With modern vehicles equipped with oil life indicators and tire pressure monitoring systems, it’s no surprise that oil changes and tire rotations are at the front and center of our minds when it comes to routine maintenance. But, now that you know how vital your vehicle’s exhaust system is, we hope you’ll add it to your list of routine checks.

Proactive maintenance is always key, and that’s especially true when it comes to your exhaust system. We recommend having your exhaust system inspected by our certified technicians every 12 to 24 months. During the inspection, we’ll look for signs of rust and other potential problems. Of course, if you notice any issues before then, like unusual smoke or odors, then don’t hesitate to bring your vehicle in for a quick inspection. With your diligence and our expertise, you’ll get the most out of your vehicle for many miles ahead.