02 s10 blazer wont start

my blazer is a 02 s10 blazer 4 wd 4.3 automatic had to change converter then had check engine lite on checked it came up as 02 sensor and maf sensor so now was running great it stalled now wont start at all battery is good has spark fuel pressure is good just wont start any ideas before i spend a lot of money

What is the fuel pressure and how long does it hold?