[99`_grand_am]

does anyone happen to know what that means? i took it to autozone and they pluged in the little thinggy that tells you why the service engine soon light is on and it said that "RPM is set higher than the operating conditions" what does that mean? is it just a sensor gone bad? and if i keep driving it will i do more sensor damage? also as i stop the engine trys to keep the rpms at about 1300 and they should actually be 1000 and it makes it a little hard to stop with the engine pulsating and all. thanks