Car runs smooth at idle and when cold once warmed up to running temp it loses power and backfires when trying to give it gas and also bogs down more. Has not stalled out yet, just acts like its going to. Replaced fuel pump, valve cover gasket, coil pack, plugs, wires, the coil pack electrical connectors, and tried a fuelx treatment.

 

If the engine is running lean result can be all the symptoms you described.
The better way to confirm fuel syst operation is to hook up a fuel pressure gauge and actually see what is going on.
If a fuel pump is not receiving a good ground connection , the pump doesn't work properly and a good working fuel pump gets replaced and the problem is still present, gets kinda expensive. You need to tackle one possibility at a time and verify correct operation then move on from there if necessary.

 

My old fuel pump was busted at the bottom, no matter what I've tried I still can find the issue.

 

How many miles on it?
And when was the timing belt last changed?

Have you cleaned the intake plenum?Throttle Plate?
Have you cleaned the Idle Air Control?

 

140,xxx. Just got the car in February don't know when timing belt was last changed. It's not stretched or anything tensioners seem good. I did spray carb cleaner into the intake and such.

 

Going to be testing the cats more today. I have to go out of state so need this car asap. Have noticed that when it acts up if I shut it off and start it right back up it seems to run fine for all of 2 or 3 seconds and goes right back to the same.