Whats the most usual problem for hesitation?

My fuel pump was dying for a while, and I have a feeling the engine was running lean to long that I might have damaged the plugs. I changed the plugs and wires last year november, so like, 7 months ago. Could it possibly be my wires/plugs or something else?

Its been happening for about three weeks now. I've tried both regular, premium, and fuel stabilzers.

 

You did not say how many miles on car. A cloged fuel filter is possible,and cheap wires can break down that soon. If the wire breaks down it fowels the plug. Also a coil pack that is going bad can give hesitation. Is there also a backfire or just hesitation?

 

I replaced the fuel filter when the fuel pump went, last month. And the car has 110,xxx kilometers. So around 68,xxx to 69,xxx miles.
No backfire. Just hesitation. And its worse under light accleration, where as under hard accleration it just doesn't seem to have the same power and is a little slow off the line.

 

Bad cat can cause loss of power also.

 

Yes, you are right there as a candidate for a plugged exhause system (cat).

 

Definetly get cat checked