Until it clogs to the point where it prevents exhaust from freely flowing through it.
Don't let your car idle for long periods of time.
No.
Yes it does.
Not likely but possible.
Yes. Oil is hard on Catalytic converter.
no it will run rough and stall out
i just had my car in for a service, they told me catalytic converters were bad and there are 2 of them , so 2.
It is one of many possibilities.
That is possible.
A car can backfire and die if the spark plugs are bad. The car could also have a problem with the timing or the catalytic converter .
Yes, a bad cat can cause issues.
Yes, if it is clogged very badly.