Thanks for the quick reply. I did a pretty thorough search at Avic411.com a few months back, and there really wasn't much info. Guys had tried the Garmin and Parrot mics without much success. I called Pioneer and he advised me to try a Garmin. Nice huh, Pioneer knows it isn't working well, so instead of fix the problem or come out with a better mic, they advise you to buy another brand mic.If that is a common Pioneer problem, I would try a search over at avic411.com if you haven't already.
Anyway, I would like to try the OEM mic, just wondered if you could leave the amp installed or if that would harm the HU.