question for mechanics... 99 se 2.4

[99`_grand_am]

my 99 se 2.4 has a problem, the service engine soon light was on, so i had that little computer thing tell me what was wrong, it said the code was p0507, and that's the code for , the rpms are set higher than the normal operating conditions, so what does that mean exactally? because it;s trying to idle higher, and that is causing the engine to pulsate as i stop, or start to go lower than about 1300 rpms, and it's really annoying and kinda hard to stop to hard, any answers on how to fix it?

[xeroinfinity]

maybe its the IAC...(idle air control) its on the right side of the throtle body. It can be cleaned if you remove it from the TB with some carb cleaner. If that doesnt work u'll hav to get a nw one.

[Gir-_-]

This brings my attention up... sometimes when stopping or going in reverse slowly.. my car will suddenly rev and go faster as Im pressing on the brakes... odd