MinisterofDOOM wrote:Easiest way to figure out why your CEL is on is to go to your favorite auto parts store and have them scan for codes.
Actually, the easiest way to figure out why the light is on is to put your ECM into the test mode (by using the test mode selector screw on the side of it), and count the light blinks to get the diagnostic trouble code(s) yourself. After doing this a number of times over the 15 years I've owned my 95 SE, I can do this in less than the time it takes me to drive the one mile to my closest Auto Zone.
After looking up what the causes of whatever diagnostic code you retrieve might be, you can then decide whether you want to try and fix it yourself or have someone else (up to and including possibly even a dealer) help you. I've also learned over the years to just reset the light (using the test mode screw and, of course, after reading the codes) the first time it comes on, and see if it comes back on again. Sometimes something fluky that really isn't a problem sets the light off. If the light comes back on, then you know you really have a problem that needs to be checked out.