I took my 2000 Ford Mustang 3.7L in to read codes, then cleared (bad EGR) Then I went to have my Car smogged and they told me it passed, but that it had been to soon since clearing the codes (Smog test computer came back with "System's Not Ready" and told me I have to bring it back within a month (basically saying they won't let me pass until the "System's not ready' code clears - How long does that take, or how can I expedite this?

Thanks for any help I can get.