Yes.
Yes there are.
It could, yes.
No, the catalytic converter has nothing whatsoever to do with your defrost system.
On some cars it could, depends on code.
A bad torque converter can cause slipping gears. The fuel mileage will suffer as well, and the engine will rev higher.
No, it will not cause the engine to knock.
it is ok to continue driving the vehicle while the catalytic converter is not working properly?
torque converter can cause this. you will have bucking and stalling. another thing it can be ( I know this to be true as it happened to me) is the cat converter.
Loose converter bolts or a cracked pressure plate.
loose or missing torque converter bolt to the flywheel
P0743-TORQUE CONVERTER CLUTCH SOLENOID/TRANS RELAY CIRCUITS This code will set if the voltage detected on the Torque Converter Clutch Solenoid Control circuit at the PCM is different than the expected voltage.
Either the solenoid pack or most likely the torque converter itself.