You can get replacement battery cable ends just about anywhere that sells auto parts.
It sounds like you may have more than one problem. Check all of your engine grounds. Make sure they are clean and tight. There was a lengthy thread recently on the subject of fixing bad grounds or adding a better ground cable.Try a search.
If it's still popping through the intake after this, you need to address that problem. Try the above first.
Your ECM may have learned to idle with a dirty IAC passage or coked up throttle bore. now it has been reset and is trying to idle on the default IAC position. Get some carb cleaner and clean it up. It' s best to remove the IAC from the throttle body to clean out the passage and the IAC pintle. The throttle bore can be done with carb cleaner and a toothbrush. Hold it open, and clean the area where the blade hits the bore. avoid spraying the TPS with carb cleaner. Once you have fixed the other problems, disconnect the battery again for a few minutes, reconnect and go for a drive to relearn the idle (you may have to 2 foot it at first).
These are generic suggestions, but without seeing the car... It's worth a try. Good Luck
[This message has been edited by Jakesdads86gt (edited 10-07-2004).]