What you have done here is upset the factory's careful attempts at
insulating the interior from engine vibrations.

What you want to do is apparently achievable with something called "K-Pro".
This thing raises the car's idle to help correct for the deficiencies of
your aftermarket engine mounts.
http://www.hondata.com/kpro.html

This may help somewhat. Although the AC will still automatically turn
on, but you can turn it off by pressing AC button.

(1)     Turn Car Off
(2)     Turn Temperature Knob To Full Blue (All the way to the left -
Counter-Clock Wise)
(3)     Turn Vent Knob To Off (All the way to the left - Counter-Clock
Wise)
(4)     Hold Down Air Recirculation Button As Well As A/C Button. NOT
THE
DEFROSTING BUTTON.
(5)     Turn the car on to two (ll) . The recirculation blinks ONCE
and
the AC blinks once.

You will now have control of your A/C regardless of what setting you
are in, to revert back, simply repeat the procedue.

Make sure u hold on to the two buttons before u turn on the car. Hold
it till after the AC button blinks. The recirculation button blinks
first than the AC. Make sure ur not holding on the Defrosting button
for the rear window