06 Pilot EXL: I turn the radio up using the knob on the stock radio, the volume goes down, I turn it down, it goes up a few notches, is this an easy fix or is it just internally worn out? Couldn't find anything when searching.
One thing to try is tuner cleaner spray or contact cleaner spray. I still have a couple of cans from Radio Shack, which in a few years more might fetch a pretty penny on a memorabilia auction site, but for a more contemporary version try here:
Be sure you get some that is quick-drying and safe for plastics.
I've never tried pulling out the volume knob on my Pilot's radio for better access to the control behind it as I often do on my hi-fi equipment at home, but perhaps you can try depending on how brave you are. In either case you'll have to use that little straw, probably drop it, swear as you try to find it, and replace it again in that tiny [insert Samuel L. Jackson's famous modifier words] hole. Then turn the knob back and forth all the way up and down for a minute or two to spread all that juice around in there. Whether you do it with the radio on or not is up to you, but for the sake of your ears and your speakers I'd recommend off.
If that doesn't do it you may have to remove the trim, pull the radio unit, and disassemble it for a more thorough cleaning.
I took some wd40 contact cleaner with the tube, sprayed it down around the radio knob with the key off, twisted it around about 20 times, turned it back on, FIXED! Woohoo!
You may want to try it first with no wd40 by just turning the key off, then pushing the knob in hard like you're turning it off, keeping the pressure on it, and spinning it, this may be enough to clean it off too, not sure.