So I have a 1984 toyota pickup I just replaced the fuel filter and fuel pump about a week ago. And the cat is about a year and a half old, sometimes when I try and start my truck it has a hard time starting.. does anyone know what this could be? I am thinking that maybe the cat is going bad because when I go up a incline it looses a lot of power

 

I would not suspect the cat if it is only a year old unless it is a poor quality or took some damage recently. I don't know the carbs that well but the factory Aisin has some pivot points can wallow out and cause some vacuum leaks. I would suspect you have an issue in the carburetor.

 

Your cat is not the issue.

Your choke could be malfunctioning,(Asian carbs have a fairly complicated choke system) good idea to get a manual and follow the fuel system guides for checking the choke components on the carb)

Changing fuel system components could of lessened crud up clogging the jets

If I were you I would replace all the vacuum lines anyways... Super cheap from Napa and would be good maintenance while your under the hood anyways.