When you clear the cell their is a record of it and will report as not ready. Most states will allow 1 or 2 not ready statuses. Also I believed the OBD2 system will hold I formation that you cleared a cell until you complete a full drive cycle.
2001 ZX3 2.0L Zetec-
Hatch Nation #42
Going through Rebuild See "The TICK Build Thread" for details (http://www.focusfanatics.com/forum/showthread.php?t=289168&referrerid=62897)