My cavalier won't idle

Pull the OBD trouble codes, even if CEL not on. Any parts place can usually do this for free. There's too many variables involved to just throw out guesses with so little info. At the least clean your throttle body, clean and replace sensors and filters. If it has been a while replace the fuel filter. Clean the MAF sensor using a MAF-only cleaner. (carb cleaner can destroy it.) See how it runs after doing all this.

The answer above is a good one ,if no codes replace fuel filter, clean throttle body, you don't have to take it out.look it up on facebook, have a good one !