answer on this site for the code:
Headers even with no leak will cause that code often. Something to do with more flow and the O2 sensor has trouble...
Ah. Yeah naw the two things are unrelated. I think you have a poor power connection to the stereo, thats all. Does it ever cut out going over bumps?...
If at any point the steering wheel or driver's airbag has been removed, a possibility of damage to the plastic tube that extends from the clockspring...