for 1 because thats a converter efficiency code, does not affect the way the engine runs and the sensors are much cheaper
for 2 because cats are designed to be 'lifetime' parts 100k is not the EOL for a cat converter, i have 118k on mine, my old dakota went over 200k before i sold it, with the factory cats still installed, cats dont go bad that quickly unless you have a running issue which is dumping excess fuel into them, or oil or something else that will damage or clog them, it is VERY uncommon for the cat to be bad

 

Pressed parking brakes does not fill hard goes down really easy does anyone know what I need to do .i know that the emergency brakes are there for a reason .please let me know thanks..also I have a very hard first time startup it will start up on the second try but it sounds like it misses. Had a tuneup change one of the elecrtronic coils. How often does the electronic coil have to be changed I have 173,000 mile on my durango 2001 4.7 2 wd