Chrysler Repair: Chrysler 300M will not start, o2 sensors, chrysler 300m

Question
I have a 99 Chrysler 300M and over the past 2 months I have been have problems with it stalling, losing power and shutting off while driving, and taking about 10 tries with a little time in between before it would actually start. I took it to Advanced Auto and the gentleman told me that I had a faulty spark plug and my O2 sensors need to be replaced. I had a tune-up done on Sat. and 2 belts replaced; however the car is still acting up. What could it possibly be? I've been told by some that it could be the fuel pump, but I want to be for certain.

Answer
yeah passable fuel pump.  DO this when u have  hard start  turn the key over 3 times with out starting it  u know key on  then key off  that will primp up the pump and u should start right away if its the fuel pump. It wont help u any while driving down the road but if its the pump it will help with the no start.
If u live near Atlanta I can look at this for u