Well if it was a fuel pump it would also be hard to start, not only stall.. So like the others said you might wanna do the MAF as well ( replace known good with possible bad to rule out scenarios )
If that doesn't work what Trevor said sounds like another great option...
If you wanna check fuel ( if it will run for a while ) drive it with a fuel gauge in it coming out the hood ( in a safe place ) and watch the fuel pressure to see if it drops / fluctuates too much.
Ps: If its hard to start; cycle the key a few times (without starting it) to build up fuel pressure, it might be a weak pump thats on its way to dying
You will figure this out
