Im sure this has been brought up before but,

02 ram 5.9 magnum. When in park the idle with go between the normal 600ish rpms to almost 2k. However when i rev it once that goes away or it eventually settles down. I know our trucks are not electronic throttle controlled so am i looking at a sensor?

 

I think Hammer would say plentium (sp) leaks?

 

Look down the throttle body with a flash light. If you see oily residue then Yuri Plenum gasket is blown. Very common on the Magnum 3.9, 5.2 & 5.9 engines...

 

Is that the gasket that is between the block and the intake manifold?