Toyota Repair: 1990 4Runner 22RE miss at idle, manifold gaskets, distributor cap

Question
Hello,
My 1990 4Runner has a hard "chug" miss at idle.  There is a rattle at the top front of the intake also.  I have to set the idle fairly high so it won't quit.  Could this be a plugged catalytic converter, a sticky valve, or what?  Thank you for your time.

Answer
Could be a leaking valve, I would recommend having the compression tested to see if there is a loss of engine compression, if that checks good start looking at basic items like spark plugs, plug wires, distributor cap, rotor.
These engines also had a history of leaking intake manifold gaskets near the #4 cylinder.