2002 Z24 Check engine light

I have a 2002 Z24. I'll give you the story from the beginning. Last week my battery was dead (left lights on) so I went to charge my battery with a plug in charger (battery still hooked up to car). After I hooked it up the car alarm went off and the trunk popped open. Then the next day I noticed that my clock was off by an hour I just wrote this off to the battery that was dead before. It ran fine and the battery was fine after that. Last night though I noticed that my clock was once again off by roughly 3 hours. Now this morning driving the car the check engine light came on. Its not the gas cap, etc. I'm starting to think it might be something to do with my electrical system somewhere that might have got messed up while jumping the car when the battery was dead? Anyone know what might be wrong? Thanks

And the cel code is?