Your exhaust system is a complicated part of your vehicle. It is made up of an exhaust manifold, oxygen sensor, catalytic converter, hangers, exhaust joints and a muffler. The main purpose of the exhaust system is to direct fumes away from the vehicle. The muffler helps keep your vehicle quiet. A series of small explosions take place inside of the exhaust system, which is why the vehicle would be noisy without a muffler.
Decreased fuel efficiency is a sign of an exhaust problem. If the fumes are not carried away from your vehicle, then your engine will operate at a hotter temperature. This can cause it to burn fuel more quickly. You may also notice vibrations that come from your gas pedal or steering wheel. This problem is likely caused by an exhaust leak. Vibrations are a major concern because they can make it harder for you to operate a vehicle.