1998 Chevy Astro High Idle

I have a 1998 Chevy Astro V6 Vortec 4.3. It has a very high idle at approx 2200-2500 RPM all the time. I replaced the Mass Air flow sensor, the Idle control valve and the throttle position sensor. I have sprayed the engine with carb cleaner to check for air leaks with no luck. As for codes... The first one I got was about the Mass air flow voltage, so I replaced it. The second code was about the throttle control had low voltage so I replaced it. I replaced the Idle control valve because the old one was fried. Please help. Call me at 760.880.2552