Answer: This necessary maintenance is important to make sure your vehicle isn’t releasing harmful gases and substances. If there is any damage to your pipes, your vehicle can be releasing harmful gases. If your catalytic converter isn’t working properly, your vehicle can release very harmful gases such as: carbon monoxide, which is an odorless, poisonous gas that can be deadly; hydrocarbons, which are a major contributor to smog; and nitrogen oxides, which are contributors to smog as well as acid rain. Also, if your muffler is damaged or isn’t working, your vehicle will be very loud. If you have ever heard a vehicle driving down the road without a muffler, you know how loud your vehicle can get. It is also important to note that any damage to any part of your exhaust system can lead to your vehicle not passing emissions tests.