How Does My Car’s Exhaust System Work?

We get a lot of exhaust questions at Sun Auto Service centers, and we have no problem answering them. However, we also know some of our clients don’t have time to swing by the shop to satisfy their mechanical curiosity. That’s why we’ve put together information about the components and shop work associated with the most common automotive systems. Here’s an introduction to your vehicle’s exhaust system.

What It Does

what is a car's exhaust systemA vehicle’s exhaust system is fairly simple when you look at the primary function. It’s essentially a long metallic tube that takes byproducts of combustion towards the rear of the vehicle. Basically, every combustion engine, from old-style steam locomotives to your vehicle’s motor, implements an exhaust system in one form or another. Without this durable pathway, all of the unburned gasoline, heat, carbon and nitrogen oxides would deposit directly into the immediate environment of the combustion process. In the case of your car, that would be your engine compartment. The exhaust system exists primarily to keep you healthy, protect the environment from contamination and prolong the life of your engine.

Environmental Protection

Ideas about protecting the environment have come a long way. Back in the industrial era, people were content with simply building higher smokestacks to keep smoke out of the streets. These days, we have sophisticated chemical and mechanical devices that change the composition of noxious and dangerous emissions. Here are some of the ways this new technology has been incorporated into your vehicle.

A Catalyst for Change

The catalytic converter, or “cat” for short, is one of the most recognizable parts in modern exhaust systems. Most car owners will have to replace this part at least once: They last about 100,000 miles. However, cats are known to fail occasionally, usually due to exhaust leaks or external damage. If you start hearing a rattling or shaking sound while you’re idling, come on in to a Sun Auto Service center and ask one of our technicians to take a look at your “cat.”

These parts are notoriously expensive, but there’s a good reason. Catalytic converters essentially break up waste gas into harmless components by using a specific type of chemical reaction made possible by a metal catalyst. The catalyst needs to be made of a precious or valuable metal, such as cerium, platinum, rhodium or manganese. You’re probably familiar with platinum’s high value from jewelry. Manganese is used in glassmaking, rhodium is necessary for certain laboratory equipment and cerium is a valuable element of petroleum refining. Since there’s high demand for these metals, it’s crucial to recycle your catalytic converter whenever it needs to be replaced.

A Question of Volume

The catalytic converter is just the first step in a car exhaust. The next major component that you’re likely to find is the muffler. Apart from power, heat and exhaust gas, your engine pumps out another product in significant quantities: sound. Your muffler reduces the sound of your engine, but there’s more to it than that. The main challenge in muffler technology is reducing noise while maximizing airflow. Better flow rate translates to better performance across the board. This balance between airflow and volume comfort is thrown out of whack when the muffler develops holes. Keep your horsepower at maximum by maintaining your muffler in good repair and replacing it when necessary.

A Resounding Success

Resonators are similar to mufflers in that they change the vibrations coming out of your engine. Where a muffler reduces sound, the resonator organizes it and tunes it. This might not seem like the most crucial component at first glance. In reality, it plays a big part in improving exhaust flow efficiency. That improvement leads to better performance and fuel efficiency, just like a well-designed muffler does. Resonators also happen to make engines sound great in the process, giving your engine its characteristic roar or purr).

The Best of the Rest

Apart from the three major components above, exhaust systems contain many pipes, clamps, hangers, and sensors. Depending on your vehicle, you might have several oxygen sensors monitoring exhaust and regulating fuel-air ratios. Flanged head exhaust pipes, connectors, and tailpipes carry gases when they’re not being processed. Air injection parts regulate the pressure in your catalytic converter. Finding an exact point of failure is a systematic and complex process that involves checking for leaks and testing components. It takes knowledge and practice to get it right, and that’s why we’re here at Sun Auto Service. Turn that rumbling smog into the fresh air and good vibes: bring your exhaust issues to us.