Do I have to fix P0171/P0174 What could happen?

My 2002 Windstar CEL came on about a month ago I bought a code reader from Canadian Tire and I read the P0171/P0174 codes. Is there any damage that can be caused by not fixing the reason for the codes? I'm not very skilled when it comes to mechanics and I really don't have the money to spare to get it fixed properly.

Thanks everyone for your input.

if you look at the sticky post at the very top of the forum, you will see lots of information on the fix itself.

my biggest issue was that I could not get my registration renewed with a CEL on. Your situation might be different. In my case, my van was running perfectly well while others report a variety of symptoms.