My car bogs bad and I get some ping from the motor when the car is warmed up. It's a fuel related problem.

Here's the deal. I replaced the fuel filter and ran some fuel injector cleaner through my system. I'm starting to think that it's the fuel pump that's going out. Shouldn't the motor bog when cold and when warm? My motor only bogs when it's warm.....

I changed the plugs, fuel filter, checked the cap/rotor, replaced the O2 sensor.