My truck was running rough at idle, checked for vac leaks and when I take the line off the egr valve it smooth out. My brother said that I can just delete it. is this ok or do I have to replace it

 

Rough at warm or hot idle ? Do you have any State emissions ?

 

Rough when you start the truck. No emissions here

 

EGR works after the engine is warm

 

No

 

I think that what he means there is that the EGR is supposed to work when the engine is warm. It's not supposed to work when the engine is cold. It's computer controlled so it could be as simple as a faulty temp sensor (ECT). Have you pulled the codes ?