1. I'm nowhere near SoCal area, can't help you on this.

2. Like what VRGNCD5 suggested, go to AutoZone for free ECU reading to determine the cause of your engine light issue.

3. First sound, perhaps a crying baby nearby! :naughty:
Second sound, not really sure about this but worth checking. The under carriage sound might be caused by a loose heat shield, right above your catalytic converter unit.