1996 Ford Contour starting and stalling problems

Hey, I have a 1996 contour 4 cylinder and at first it would stall for no reason while driving. After a minute, it would start up again and be fine. In the morning, it would start, idle, then stall. After a few times of this, when the engine is warmed up a bit, it starts better and idles longer. Then when the car is warmed up, it works perfect. Until now. I changed the spark plugs and wires, but i didn't do the plug 1 and plug 4 cross.
Should I?
Now the car would not start. Can anyone help me in this matter?

try the O2 sensor

Sounds like A problem I was having. Except mine rarely stalled. I Started it up and when it idle down from choke it seemed like it was going to die. My problem ended up being my Mass Air Flow sensor. The little wire that does the sensing was covered in something giving a false reading. I cleaned it off with intake cleaner and it runs great. It still idles low after it warms up but it doesn't sound like it wants to die.