There are many causes for a CEL, but it does not come on to remind you of maintenance needs. The CEL is linked to the Powertrain Computer Module (PCM)which monitors various conditions thru the use of sensors. If the PCM gets readings that are known to be an "out of spec" issue, usually emissions related, the CEL will come on. If the problem is intermittent, the light may go off, come on again, etc. In any case, the "On Board Diagnostic" system will record the error code, which can be read by the proper reader-scanner. A code number (or numbers) come back, which will then have to be diagnosed. The most common issues on the V6 are O2 sensors that go out of spec and send a wrong signal to the PCM. Also the EGR ports behind the throttle body get carbon-plugged and it appears that the EGR is not opening. Get the code(s) read at Autozone, and then do a search of the posts. There is lots of info on the CEL! Good Luck.
