Considering how many "CD Error" threads there have been over the years, you may want to seriously consider starting with a new head unit, and go from there. I think there are a couple that, with the right harness, will plug into the stock system and provide improved sound, along with mp3 capability.
I have had cd error messages over the years and simply put up with them. If I ever upgrade my stereo system, I'll do as described above.