I have 2005 Mitsubishi Galant GTS and I went to Auto Zone to get an answer as to why my check engine light came on. It says code: P0455... evap system large leak detected. Now I'm not too familiar with this kind of problem. I'm wondering how long can I go without getting it fixed? I have an important meeting in Atlanta, GA and I'm driving from Charlotte, NC. After my meeting I'm taking my car to the shop to get it fixed. Will I be OK or should I rush it in? What is an Evap leak anyway???? Thanks in advance for all responses that are returned ASAP!!!

Kia