I have a 1996 jeep xj and it has had this problem of a high idle lately. I don't have an rpm gauge so I can't tell I can just hear. I replaced the tps sensor as well as the idle air control valve and cleaned the throttle body itself. There doesn't seem to be any vacuum leaks but while running if I play with the throttle enough I can get it to go down to regular idle. Any suggestions?

 

Try spraying a bottle of water around the intake to figure whether air is by-passing. Water should bog the engine and clean the pistons, too.

 

after air filter or before air filter?

 

I have a 96 with idle issues from time to time, and I have come to realize it is not just one thing that will mess with the idle but rather many - all the rubber caps and connections in the intake manifold should be checked for cracking and leaking. The same for the grommets on top of the valve cover. Then the oxygen sensors (have you checked for any codes?)

Lastly, if you plan on keeping the Jeep long term, swap out the instrument, gauge cluster for the one with all the dials and needles. It makes a big difference in monitoring engine performance. Or get that Torque app connected to your phone to see how high the idle is. Without knowing the idle RPMs you are wasting your time.