It was accidentally fixed! when I put filter as face and clicked on it, it only selected that part, and I was able to simply delete it. I guess it was a face left over from my subtraction. thanks for your advice nevertheless! that's a way I couldn't think of. 

Hi, I'm a beginner in autocad. I was editing a solid using subtract, and for  some reason there was a tiny bit, something that looks more like a face than a piece of solid, left over( Below picture shows where it is). I tried to get rid of it by putting another solid over it and subtract, but it didn't work. Then I tried using separate to separate the tiny leftover piece from the bigger solid, but it didn't work. I'm guessing that's because when you used subtract to edit, it is not completely separate to make them into 2 separate entities?  If I use slice I can get rid of the small leftover piece, but it ends up cutting other pieces in the structure that I need. 

Edited by eahn - 26.Apr.2011 at 18:19