I have a 2002 Chevy Malibu V6. Recently my check engine light came on for about a day and when off the next day. I then when to my garage and they plugged it into the computer and road tested it with the computer hooked up. They could not find anything wrong and charged me $100.00. Could there be a misfunctioning connection or a bad wire? If so could I find out where the wire and connecters are located so I can replace it myself?

 

It could be over 100 different things. Probably was a sensor that went out of range, and then corrected itself, turning out the light. Although you can usually pick that up through the history codes. Best thing to do is bring it in when the light is on

 

Could someone get under my car and pull one to light the "Check Engine" light? Is there an electrode connection accessable to the engine from under my car?

 

Its possible...but the light wouldn't turn off if they did

 

I would Just leave it alone and if only if it comes back on or car acts up dont worry about it. Emmisions alone can trigger a check light and w/o the specific code thrown/ dummy light on when checked it's immposible to tell its origin and it sounds like it resolved itself quickly