Yes the cat does sound like it but lot of other things it can be
if cat plugged car would stall with any driving condition
this could be the result of fuel filters in take on chassis up by engine
air filter
elevation changes can make cars wonky
along with that on a hill gas goes to lowest point in tank
if you had half a tank your filter would be picking up fuel like it was thinking empty this is why little preasure pumped into gas tank to help change that
worn sparks plugs
engine needs overhaul
transbands
turn off ac
ac failing
battery failing
alternator not charging complete
air intakes clogged bad sensor
idle control sensor giving out
these are the basics why
take to mechanic and have them check out vehicle

Chack catalitorconverter to see if pluged