Thread: radio deck does not read disc

Alright the girlfriend has a 99 grand prix gt.
puts the cd in the deck and it will read it 20% of the time. the other times it just spits the disc out and showes E20. which i figured it meant error 20. and when it does play it just skips alot.
What could be wrong?
And am i just going to have to put a new deck in to fix this problem for her?