Exhaust systems have four main functions: to control noise, to direct exhaust fumes away from passengers, to improve the performance of the engine and to improve fuel consumption.
An exhaust is a series of pipes that links the engine to a muffler and catalytic converter.
The tailpipe is the only part of the exhaust that you can see extending beyond the back of the car. The muffler attaches to the tailpipe, then a series of additional pipes join the muffler to the catalytic converter and finally the engine.
Your cars muffler is made up of metal plates or tubes that have a series of holes drilled into them. Exhaust gases leave the engine at very high pressures, and the holes in the silencer help to reduce that pressure so that they leave the car more quietly.
Exhaust systems will normally corrode from both the inside and outside. The expected life of your exhaust depends on how far and how often you drive your car rather than the length of time it has been on your car. Short trips around town tend to corrode their exhausts in a much shorter time and distance than cars used more often for long journeys. This is due in large part to the fact that there is moisture present in exhaust gas. This moisture will stay inside your exhaust system and begin to have a corrosive effect on the metal components. Short trips do not allow for significant enough heat to build and cause the moisture to evaporate. Cars that are driven regularly for extended trips are less likely to fail prematurely due to corrosion.
The oxygen sensor measures and sends exhaust gas content information back to your cars on board computer. This computer makes second by second adjustments to the fuel and air mixture being delivered to your engine. If the oxygen sensor fails, the on board computer sends a default amount of fuel to the chamber, similar to driving with the choke on. This will tend to negatively affect fuel economy and create an environment where your car may not run efficiently or smoothly. A faulty oxygen sensor will normally cause the service engine warning light to show on your dash. This light means that a diagnostic scan of your computer is in order. A diagnostic scan will share trouble codes with your technician and allow them to accurately diagnose the problem. It is important to ensure that your vehicles oxygen sensors are reporting properly. They will wear over time and become contaminated. Oxygen sensors have a normal useful life of between 75,000 and 100,000 kilometres.