my dually ran great last night
 

I have a 03 power stroke 6 liter last night it ran great this morning it would not sstart I changed fuel filters and now nothing it was trying to start then nothing any help

Need more info. . Does it crank over properly? Do a ficm test, usually when they go bad voltage drops. Easy test at top of page. You can use scan tool to read ficm voltage also. Test ficm and fuel pressure. There is test port on upper filter and you will need adapter. Start with the basics!

Also check to make sure the oil pressure guage is coming up when you are cranking it, if not we can walk you through a simple test to make sure the engine oil pump is good.