Nissan Repair: 97 Nissan Quest wont start after warm, fuel pressure regulator, oxegen sensor

Question
My 1997 Nissan Quest will start and run fine when cold. As soon as it runs for 15 or 20 minutes it will start running rough and then die and it won't start untill it cools down. I have replaced the the fuel pump, fuel reg, catilatic converter, coil, and ingnition module. When it gets warm and dies it smells bad like rotten eggs. I have been told that it could be a computer, distribute, or egr valve. I am wondering if it is carbon build up. The garage I took it to can not find the problem. They have had it on the computer and it shows a oxegen sensor is bad, but I have not replaced it yet. Could that cause the problem? Need help. Thanks

Answer
Bobby,

The oxygen sensor could be bad but I think the fuel pressure regulator is defective since it runs when cold but when warm it gets too rich.  Are there any codes showing other than the oxygen sensor?  Email me back once you check the regulator.