Evap Leak?

[The Creature]

Hello all, I just joined this forum in hopes that i can meet and chat with fellow GM heads like myself. I have a 2004 silverado with a 5.3 in it, trucks been a tank for the 7 years i owned it..but i've had a few minor blips on the radar. Hopefully some of you will have some advise

 

1) my service airbag light and message were stuck on for a few months, then it just went away..not really sure what was going on there, i checked under the passenger seat and did not find any exposed wireing(passenger seat is rarely used) and i crawled under and looked at the two little boxes under the bumper, which both appeared to be free of corrosion..so i'm at a loss here, the light disappeared about a month ago again.

 

2) currently i have the dreaded evap leak(had it scanned and it faulted 3 times on "small evap leak"..now i know that this does nothing as far as performance or anything but its annoying seeing this light on lol, here is the kicker though..it shutoff and stayed off for about two weeks then randomly came back on, i have not gotten gas recently as i only fill up about once a month..any ideas?

 

3) i installed an aftermarket cd player recently, and found that the previous owner had left what appears to be audio/visual jacks packed back into the dash, and had ran power directly from the ignition to the whatever he had in there before...then when he or she put the stock radio back in, left the hot power wire exposed and floating around back there, does anyone think this would have damaged anything? the wire now is powering my new cd player but man was it scaring when that thing started arcing lol