The computer run a check every time you start the engine
and if detect any malfunction in any of the monitors it will turn the check engine light on it warn you of it
its could be a simple vacuum leak to a major as converter no good or so on '
that why u need the codes
next time the light comes on have it scanned for codes
post it and we will let you know what is the issue
Sunday, May 25th, 2008 AT 10:08 PM