Mitsubishi Repair: clear check engine light, negative battery cable, nissan maxima

Question
97 Galant
Autozone diagnosed my check engine light with a P0442 - Small Leak EVAP. As I troubleshoot the problem, will the check engine light automatically turn-off if corrected? If not, how do I clear it? Do I simply disconnect the battery?  
Thanks.

Answer
Sean,
That error code is fairly common.  I had that same problem, but on a Nissan Maxima I once owned (I'm not exclusive to Mitsubishi ;-) ).  The problem was a simple valve that would open and close when the car firsted started.  It was to regulate ventilation of gas pressure.  You will probably not even notice any performance change.  It's just for emmissions regulations.  You may get lucky and find the problem is just a bad gas cap.  Check the rubber o-ring around the cap and see if its cracked or brittle.

Even after you fix it, the check engine light (CEL) will not automatically turn off. Disconnecting the negative battery cable for about a minute should reset the car's computer and CEL.  But if the CEL comes on after only driving a few miles, then that means the problem is not fixed yet.  Once you are confident you fixed the problem, and if you cannot turn off the CEL yourself, the folks at AutoZone should be able to turn off the light using the same scan tool they used to find the code.
Good luck!