Ignition coils went out causing random engine misfires. Replaced ig. coils but a gasket in the exhaust system blew out already. Replaced gasket and fixed exhaust leak. Now, car seems fine. but after putting car in drive and then returning it to park, the rpms stay high around 3000 rpms... Depressing the brake multiple times for whatever reason increases the rpms somehow.. could this be the IAC valve?? This is getting frustrating! Any help would be greatly appreciated.

Again, the car idles fine in park until you put it in drive and then return it to park.

Kyle