Ok, i have a 96 mistu gst. Fully stock. About 3 or 4 weeks ago i noticed a loss in power. My headlights were dimmed, My dash lights and radio light were also dim. When i tried rolling down the windows, braking or using the interior lights, they all made my headlights dim even more. It also seems to take a little longer to start up.
I checked the fuses, they are fine.
I went to a shop and they tested my battery and alternator. I don't know how well though. While my car was running he hooked up wires to my + and - terminals and on a handheld reader, showed me the numbers.
my battery was at 12.43 volts
my alternator was charging at like 14.73 volts.

What could be causing this?

my friends eclipse head its battery go out, but his car wouldnt start. He took it out had it checked at kragen, and they told him that it was reading good voltage but it wasnt outputting the enough volts. I'm getting mine checked tomorrow.

Could this be my problem?

Also my CEL came on the code P0440:evap control system malfunction. The guy said it was prolly something to do with my gas cap. I noticed that about a week after my CEL was on, i was getting gas and i used the little lever on the gas pump handle, so i didnt have to hold the handle myself. Well it overflowed. It didnt automatically shut off. Also sometimes i can smell gas at the rear of the car.

Could those problems be related?

Please help me i need it bad.