Eating up oil

Hi, Everyone,
I have done a search in this forum and found that a lot of people are experiencing the same problem as i do

"the 2002 nissan sentra are eating up oil like crazy" :banghead:

and the reason i found is that "there was a problem with the piston rings seating on the early model 02's, causing them to eat oil"

I am wondering if it would do any harms to the engine if I don't have it fixed?

The reason is that my car has around 45000 miles on it and it's out of the basic warranty. I called the nissan customer care and they just told me to call my dealer and I don't think it will help at all.
they said they have to diagnose the car and see what's wrong with it and there's charges for the diagnostics itself. :banghead:

I definitely don't know what to do with it right now.
I wanted to know if they have done any recalls regarding to this issue.

I have brought it to the dealer for all recalls but it doesn't seem helping at all though. :banghead:

Also, does anyone have problems with the 6-CD changer that came with the car?
somehow the error message "Err 2" pops up on the screen and don't know what it means

Thanks everyone!!!