Fuel Pressure Regulator?
 

Hi All. I am new to the forums, but am at the end of my rope (and wallet). I need some help. My 2001 MPV is having some problems. Here is wha is going on:

Sometimes when we turn it off it will not start again. It just cranks and doesn't fire. If we just let it sit from anywhere between 30 minutes to 3 hours it will just start working. It has died before at a stop sign. The CEL came on recently with an error for the O2 sensor. It said bank 1 sensor 1. We replaced the 2 upstream sensors just to make sure and that did no help. The problem is still there and the CEL came back on with the same code. We have had way to many people diagnose it and I am running out of money. One person said I should replace the fuel pump and then another told me that he is postive the fuel presure regulator is bad. What should I do?

Another description. We were stuck for 3 hours yesterday cranking the engine to no avail. I was pumping the gas the whole time when my mother-in-law mentioned she didn't even smell any gas from it. It gave me an idea to push the car to an incline where the front of the car was facing down. We did that and the car started immediately after it sat for like 5 minutes. What the heck?! Is it the fuel pressure regulator, fuel pump, catalytic convertor, or really the O2 sensors (again).

Any suggestions would be gold for me at this point.

Thanks,
Phil