when you put a cd in the factory player it says "error" and ejects the cd.

 

Dirty lens? Run a cleaning disc through it.

Bad disc? Have you tried several discs? I haven't had my factory unit installed in a few years but I do remember having trouble with some home made audio CD's. Try a couple retail discs. Maybe it's just bad media.

Maybe it's just a dead unit. Buy a "new" OEM unit (make sure you get the unlock code):
http://shop.ebay.com/i.html?_nkw=hon....c0.m270.l1313

Or just buy a cheap aftermarket unit if all else fails.