Fuel filter being old/dirty would most likely cause a low and rough idle, and poor performance. Not a high idle. You can test the MAF with a multimeter, I don't know off hand what the voltages should be though, could probably find them in one of the many manuals on this site. The power steering sensor would be found there as well, but I don't know where it is myself.

I do know I was getting a high idle a week or so ago, cleaned the IAC and MAF with carb parts cleaner and blew them both dry with a little compressed air. When you changed the IAC valve was the idle fine after that, or change shortly after, no change at all? Most high idles that don't throw a code will be an IAC issue, or base idle. Is it every time you start it idling high? Or just on occasion?