H1B extension after expiry in USA

Hi,

My Visa & I94 is expiring by 30-Sep-2013 and im currently in USA, i have applied new LCA on 25-Sep and im going to file petition for extension by 5-OCT-2013. Is it valid to do it? and is it valid to stay in US after Sep-30. do we expect any issues during visa stamping process? Please help me that

As far as I know , your application should reach USCIS on or before 30 Sep not to consider you as out of status.

Legally you are not supposed to stay in USA beyond your I-94 until you have another case in pending.

IMO, Better to file extension by 30 th sep to avoid any future probelms though people are saying that USCIS may not question you for 4 or 5 days of Out of status.