I have a high idle problem that I can't resolve.

What is your question?

I am experiencing a high idle problem with my 1998 GMC Envoy (Jimmy). It idles between 1500 and 2000. It is throwing the P0102 code, mass air flow sensor. I changed the mass sensor with no change. I then cleaned the throttle body and change the idle control valve, still no change in idle.I checked for vacuum leaks and found none. Replaced the throttle position sensor and still no change. I replaced the upper and lower intake manifold gaskets and still no change. What could possibly be causing this high idle problem??