When I turned the car on this morning, it was really loud and sounded like there was a hole in the muffler. But I really could not tell where it was coming from. There also seemed to be a slight smell.
An exhaust system noise accompanied by a strange smell could be an indication of the catalyst deteriorating in the catalytic converter. The exhaust system should be thoroughly inspected, and depending on the mileage, if it is indeed the catalytic converter, it may be covered under the federal emissions warranty. You may also want to consult with a mechanic, such as one from YourMechanic, to assist in the diagnosis and repair of the exhaust system.