It sounds like crap
A clogged muffler can.
A bad muffler will do a few things to your car. First, it will make it louder. Second it will spew much more pollution into the atmosphere. This can also seep into your car and cause you to pass out from the fumes.
You get a ticket for noise violation
No it is not a bad thing. The muffler was invented to muffle the sound. The muffler does not enhance anything. However, the muffler stops the engine being noisy and it is a LEGAL requirement to have one, if you take it off, the police will stop and fine you and your car may be crushed.
Maybe the muffler is bad.
NO!
It may because of a bad/clogged air filter or muffler.
The muffler makes your car run quiet
no it will not! timming off will or high idle will.
Yes, reduced back pressure in bad for valves
Hole in the muffler.
If your car knocks, grinds, squeaks and makes other unholy noises, it may have a bad muffler. A muffler is basically a series of tubes and chambers located under the car at its back end. Mufflers quiet the noise made by the engine and reduce noxious emissions. If your car's muffler isn't working, you're polluting the atmosphere with fumes and unpleasant noise every time you go for a drive.