Car has been sitting for about 5 days and weather is in 30's. I just put anew battery in it 7 days ago. It will turn over and sounds like it wants to start. It just backfired and caught the air cleaner on fire! Luckily I got that out quick enough to not cause any damage except to the filter. Prior to changing the battery the check engine light went on. Auto Zone diagnosedthe problemas the MAP/MAS sensor and a misfire in #6. When I got in to leave Auto Zone the van wouldn't start. They checked the battery and it was only running on 1 cell. After changing the battery the check engine light went out and all thesymptoms disappeared. Auto Zone said that a bad battery could have caused all the above diagnoses. But now, it won't start. Any suggestions?