I have a 1999 Camaro it's my first car i'm 17. It has alot of miles on it i'm talking almost 136k miles. Any suggestions on what I should do to tune it up? I am asking for a slightly used SS for my graduation in May from HS. Some common problems with it is a constant whistleing sound when the car is running high pitched it comes out of one of the exhaust pipe breather things half way down the exhaust pipe under the car. . also randomly just sitting at a stop light or w/e the battery power will suddenly drop to below the middle reader thingy and the headlights and console lights all dim and then you hear it go back up. . bout all I can think of any suggestions what to do?