Vacuum leak in 2000 Hyundai

What is your question?

Replace coils , tune up , oil change , fuel pump , master cylinder , valve cover seals . But my car is still idiling rough I think I may have a vacuum leak . But how do I figure it out ? And if so how do I fix it ?

What makes this problem better or worse?

When it’s cold

How long has your 2000 Hyundai Sonata had this problem?

A few weeks