How does the exhaust system work?
The main functions of your exhaust system are to funnel exhaust fumes away, to control the noise, and help reduce pollution.
Exhaust gasses are pushed out of the side of the engine, down some piping and then out of the tail pipe
, usually found at the back of the vehicle and away from you, and your passengers.
Along the way to the tailpipe, the gasses pass through a filtering device known as a catalytic converter
or “cat”. The catalytic converter transforms air-polluting oxides of nitrogen, unburned fuel, and carbon monoxide into plain old nitrogen, carbon dioxide, and water… far less harmful by-products!
Explosions are loud! While the catalytic converter helps reduce some of the noise, to really deaden the sound of the running engine, your car has a muffler
, or maybe even a set of them. Inside the muffler you'll find a deceptively simple set of tubes with some holes in them. These tubes and chambers are as finely tuned as a musical instrument. They are designed to reflect the sound waves produced by the engine in such a way that they partially cancel themselves out. When should I replace my catalytic converter?
If your engine is properly maintained and running correctly, the catalytic converter
should last the life of your vehicle. They are made of rare and therefore expensive metals such as gold, palladium or rhodium. However, if your engine is burning oil or not running with the proper fuel mixture, the catalytic converter or the muffler can fail earlier.
While the exhaust system is usually very low maintenance, things can still go wrong.
Since the exhaust system is located under the body of the car it also is susceptible to damage and rust. A sharp blow to the underneath of your car, after say, bottoming out, can damage the Cat, the muffler, or the pipes and hangers. If you live in colder weather climates where salt is regularly used on the roads, it is recommended to bring your car through a car wash that provides an under-carriage wash. Since the exhaust system is a series of individual parts bolted or welded together, each component usually has a gasket at the place where the parts are joined together and it is possible for these gaskets to crack and leak over time. What are the signs of exhaust system problems?
Some signs that you could have a problem include: black smoke, odd vibrations, suddenly having to fill your gas tank more frequently, a very loud and constant humming noise, or a noise similar to rocks being shaken in a box. Also, newer cars will show a specific error code for exhaust system issues. Finally, if you live in an area with emissions inspections, the “smog test” will expose an exhaust system failure.