Try replacing the PCV valve, cheap and effective. When the valve gets dirty, quickly depressing the throttle will bog the engine down(pressure issues).
Not unless it was originally equipped with a catalytic converter which is unlikely. If not, then NO it is not required.
No, it is illegal to remove a catalytic converter from any vehicle unless you replace it with another one.
NO, unless it it worn out or making noise
A catalytic converter should NEVER go bad unless something causes it such as a RICH or a LEAN condition. What is a "RICH OR A LEAN CONDITION"?
Normally when catalytic converters become clogged and need replacing there is a reason for this. Something caused the converter to become clogged. Unless you fix the problem the new converter will just become clogged like the old one. If the check engine light is not on and the vehicle is running perfectly with the new converter then it will more than likely pass the smog test.
Yes it does. unless someone took it off.
You don't have to change or remove the converter unless the converter is stopped up.
I believe bank 1 sensor 1 is Passenger side before catalytic converter. sensor 2 is after catalytic converter. bank 2 sensor 1 is Driver side before catalytic converter. sensor 2 is after catalytic converter.
best if you take it to a shop unless you have a welder.
Not unless your state or local Government requires it. Has no effect on performance unless it is clogged.
You'll have to remove the catalytic converter and Y-pipe and go with straight pipes with individual mufflers. Legally you can't remove the converter unless you're replacing it, which you'll need two if you're planning on true duals (to be legal, that is)
Not unless it is clogged or damaged. You cannot run the car without a converter if that is what you are asking. It is illegal and the engine will not run properly with the converter removed.