Car has very bad idle when ever in park or n it goes up to 2000 rpm then after 30 sec it shoots up to 5000 rpm

 

vacuum leak

 

What rick_rabies said. You can get a can of throttle body cleaner or carb cleaner & spray it around the intake side of stuff/vacuum hoses while the car is running. If the engine stutters while doing so, you've found your leak.

 

Check your PCV valve