I can only comment on a similar experience with a 2001 Montana 8 passenger vehicle. While driving on a 4 lane highway and pulling into the inside lane to pass a vehicle while doing 100kph ( about 60 mph ) when stepping on the gas to accelerate for passing, I would notice a shake and what sounded like tiny explosions in the engine. It also may have sounded like the old knocking you used to get before electronic ignition. I found I cured a lot of these problems switching to higher octane gas for about 4 fill-ups then using mid grade gas for the rest of my fill-ups. Even though they state an octane of 87 is adequate, 89, 91 is better, cleaner burning, and better gas mileage. I have 1420,000km on mine and am using 9 liters/100 kilometers which is mostly highway driving.
A clogged muffler can.
The machine will be much louder and make it uncomfortable to be around. Lack of a muffler can cause you to be over the noise levels for various laws and ordinances. In many places removing the muffler from a car can lead to a ticket.
A hole in the muffler would cause a knocking sound in your muffler. A loose exhaust pipe can also cause a knocking noise.
A bad muffler on a 96 civic could cause loud exhaust noise. The muffler could cause hard starting if it is stopped up.
THATS usally cause by the engine using oil-because of bad oil rings etc.
A faulty muffler will not cause this but a clogged catalytic converter will.
No a bad muffler shouldn't, but a clogged catalytic converter will.
leaking or cracked manifold
Yes.
You may if the noise level is too high. But that is the least of your worries. A defective muffler may cause your death or at the very least an accident. A muffler with a break or hole in it will allow carbon monoxide to enter the passenger compartment of your vehicle, especially if you are driving with the windows up. Carbon monoxide is odorless and tasteless gas that kills. This will cause you to feel sleepy and will eventually cause you to loose control of your vehicle. Get the muffler replaced ASAP.
A hole in a muffler is from two causes. It has either rusted through or been damaged by something hitting it.
If there's a hole in the muffler, you will begin to hear a loud roaring noise when you drive. You also will notice toxic fumes coming out from the muffler. These fumes can cause headaches, dizziness, and other health problems when inhaled.