Yes, if it is clogged very badly.
Yes if it is totally clogged.
No.
Check that catalytic converter is not plugged
Replace it.Replace it.
Gets clogged
Engine mounts
The heat shield on top of the converter may have broken loose. it can be repaired. If the rattling is inside the converter it must be replaced.
Could b a number of problems my 98 ram started doing it and the catalytic converter was clogged
Check for plugged: fuel, air filter, catalytic converter
Your catalytic converter is plugged up. That's why it smells like rotten eggs. The best fix is a new catalytic converter. The stuff you're talking about cleans your cat. converter out but may or may not stop the smell. note: You need to find out why your converter is getting plugged up. Usually the cause is you car engine running too rich.
Yes, it measures the amount of oxygen in the exhaust as compared to the oxygen in the atmosphere. A faulty 02 sensor will make the engine run rich and eventually ruin the catalytic converter not to mention bad gas mileage.
A bad catalytic converter and stopped up muffler will slow down the car. The catalytic converter is under warranty up to 84,000 miles, if defective. If you ran over a speed bump and damaged it, you have to replace it. You can buy a lower catalytic converter for $120 from advance auto parts.