2000 alero wont stay running

i have aproblem with a 2000 alero v6 it is stalling some times it starts for a second or to sometimes it will run.i replaced the fuel filter and it has 50 lbs of pressure does anyone have any ideas thanks for some input

When this problem occurs, is the SECURITY light lit/flashing? Sometimes the keys wear out, and the passlock system shuts down the fuel injectors after 3-4 seconds. Search this forum for "passlock" problems, there are several ways to deal with it.
Hope this helps.

is there some kind of reset on the security system and how is it done.

Try Xero's relearn procedure in:
http://www.automotiveforums.com/vbulletin/showthread.php?t=894915&highlight=security+relearn

someone said it might be a ijnition module were is that at to replace