i seem to be loosing power when i come to a stop. when im ideling i just about loose power. my lights dim and all.  i have replaced and upgraded the alternater to 160amp and a yellow top optima. any ideas?
 
check your grounds
http://www.ohiocichlids.com  <<<<If you keep cichlids
 
grounds are all tight. i checked. i couldnt find anything loose.
 
then your alternator is getting weak.
http://www.ohiocichlids.com  <<<<If you keep cichlids
 
What kind of stereo do you have. I assume because you upgraded all that, that you have one of those annoying stereos I have listen to when I pull up to a stop light.
Anyways a voltage regulator built inside the alternator can cause your problems.
Get you battery tested for voltage, or if you have a multimeter you can do it yourself. An alternator test you can have autozone do for you, its free.
- 2004 Cavalier - 124k, owned since new