My guess is that the previous owner disabled the EGR. Blocked it of or something to that effect.
A blocked EGR shows up as Check Enginge.
It's common to tamper with the EGR as it is the spawn of satan. Disabling EGR gives you a cleaner engine, less sooth, better economy and more.
Research this yourself.
You might want to be sure why the EGR is in error, but I would leave EGR disabled if it was me. A good tuner should be able to make the warning not appear for EGR only.
/McK
Oh and hi. My first post and all..