The muffler is a vital component of your car’s exhaust system. One of its functions is living up to its name and muffling the car’s noise, but it does have other uses. Having a hole in your muffler has several effects, not all of them obvious and one that can be deadly.

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Noise

• Noise is often the most obvious sign of a hole in the muffler. Cars with a hole in the muffler will make loud, rumbling noises, with the noises getting louder as the hole gets bigger and the muffler falls further into disrepair.
  In some cases the noise can even include a loud backfiring noise, the Canadian Driver website notes. Having a hole in the muffler or other part of the exhaust system can cause the oxygen sensor in the fuel injection system to malfunction, the site says, sending extra fuel to the engine. This extra fuel can come in contact with the oxygen coming in through the leak, which results in the backfire.

Exhaust

• A hole in the muffler can also cause the exhaust gases in the car to seep into the car’s interior. The biggest threat is the carbon monoxide that is part of the exhaust. You won’t be able to taste, smell or see any carbon monoxide that filters into your car, but you will feel its effects.
  If you are breathing in the toxic gas, you could suffer from headaches, fatigue, nausea, dizziness, difficulty breathing and confusion, according to the Auto Upkeep website. The site says to get the car checked out right away if you suspect carbon monoxide is seeping into your car. It also notes to keep your windows open to keep outside air circulating through the vehicle if you are forced to drive before the problem is fixed.
  Carbon monoxide is especially hazardous for small children and older adults but carbon monoxide poisoning can be lethal to anyone of any age.

Pollution

• In addition to harming your car’s occupants, emissions that seep from a hole in the muffler can also harm the atmosphere. You may not even realize your car is polluting the environment, according to the Environmental Protection Agency website, which is why most states have regular inspections that vehicles must pass to be allowed on the road.

Water Drain Hole

• Some mufflers have a small hole where water drains out of its lower end. That hole is supposed to be there. The Auto Upkeep website says these small holes are known as “weep” holes and they stop water from building up in the muffler and cut down on the muffler’s tendency to rust.
  The holes you need to fix are small rust holes or other anomalies. Muffler holes often start forming near the exhaust pipes.

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