my brothers 2000 civic ex, everytime he does a complete stop it idles at 2500 for a couple seconds then drops down to regular idle. also when he shifts into neutral while driving, it drops to 2500 and stays there until he stops then it will idle normal again. i sprayed down the throttle spring with carb cleaner but that didnt help. any suggestions?

 

My buddy had the same in an H22 prelude... its pretty ---- to resolve...
TPS sensor and other miscelanious.
80% sure it has nothing to do with the throtle mechanical system

 

BTW read the idle air control valve threat its atached on top