To Many to Count (fuel pump?)

Recently our 2002 Taurus stalled. The mechanic checked it and replaced the fuel pump. The car stalled again and the same mechanic replaced the fuel pump again. Found out that what he installed an after market fuel pump.(Not the whole pump casing/plastic). He indicated it burned out again. Now it hesitates to start, takes a few cranks. He replaced the EGR valve and the gas cap, since those were the codes that needed attention also. Every so often it hesitates, like it is starving for fuel. The engine light remains on. Now there is humming sound form under the hood when I start the car and the sound comes and goes.
The mechanic informed me that he removed a check valve that sits on top of the fuel pump casing, so it wouldn't burned out and would not affect it. I wonder what he did. Thinking of shooting the car. Can some one give me some advise, replace the pump again. I will change mechanic. Time consuming and expensive. Fuel filter was replaced.

Did anyone check to see if the fuel filter is restricted or plugged?