97 Jimmy Stalling after 30 mins.

A coworker of mine has a 97 Jimmy that will run for about 30mins and then sputters and dies. If he waits for about 20mins it will usually start back up and run for a couple more minutes and dies for about 8 hrs. We replaced a bad fuel pump and filter about 2 weeks before the problems started and it ran great for the two weeks at least. It is putting out a P0131 and a P0300 code. We removed the cat and it wasn't clogged and the o2 sensors looked fine. We also replaced the igniton module and the coil is putting out spark.. Any thoughts would be greatly appreciated...

At the time it quiets check for lose of fuel pressure or lose of spark to spark plugs.
Post back results.
MT

Thanks for the quick replay. One other thing, but I don't think it is causing the problem. When we dropped the tank we didn't see the valve in the front of the tank and it broke when the hose connects. We epoxyed it back together.. What is the name of that valve? and could it cause any problems?

It is part of your EVAP emission system.
Should no make it quit running.

Recheck and test the fuel pressure.
When driving down the roat afte 20-30 minutes running and when it quits.
After market fuel pumps do not hold up very well.
What brand of fuel pump did you put in it?