Irregular idling problem with 4cyl Sonata

Can anyone give me an idea what would be the problem with irregular idling with the twin cam 2litre Sonata??

yes ,its called idle surge and a few things can cause it,plugs,wires,coil,air filter,and then while the car is running spray some starting fluid on and around the intake manifold to check for leaks! if the engine revs up then you know you have a leak, also spray all the hose connections, where the intake manifold meets the head, and any other connection that looks as if its vacuum related,cuz if you have a vacum leak that also is a cause,lets see what else,oh,isc,your idle speed control,try that