The muffler's job is to reduce the amount of noise created through your exhaust system and see fumes carried safely away, and it's one component that's commonly neglected. Of course, the muffler might not sound as important as your wheels or your transmission, but that doesn't mean that one that's gone bad isn't going to negatively affect your drive.

Just like most other components in your vehicle, the muffler may eventually need to be replaced by a car service. Here are just four signs that you should look out for.

1. Rumbling Noises

It shouldn't really come as a surprise to learn that loud noises are one of the most common signs that a muffler needs to be replaced; after all, it's their job to keep engine noise at bay. When the muffler starts to fail, you'll start to notice a distinct rumbling sound that becomes louder as you gun the engine. It will continue to get louder and louder, so sort the problem in good time.

2. Vibrations

Though it's more common to hear that a muffler is becoming worn out, you might also feel that your muffler is becoming worn out. If there's a large hole, your whole vehicle may vibrate dangerously. However, what's more likely is a noticeable degree of vibration transmitted through either the steering wheel or foot pedals, you may also feel it through your seats.

3. Reduced Efficiency

There are plenty of reasons why your vehicle might be consuming more fuel than it should, and a poor muffler is among them. Your muffler is also partly responsible for moving air cleanly through the exhaust system. If it isn't able to perform that role properly, air is going to get backed up and fresh air won't be able to get into the engine as easily. This will gradually reduce your fuel economy scores.

4. Unpleasant Smell

Finally, you may start to notice that the inside of your car has started to smell slightly off. This is actually quite a dangerous sign since it indicates that exhaust gases may have penetrated into the passenger compartment. Your muffler is supposed to help funnel those fumes out of the exhaust, but a leak in your muffler could mean that some of those fumes are able to escape the exhaust system and make their way into the cabin. Make sure you have any smells checked as soon as possible – exhaust fumes in the cabin can be fatal.