Yes a #3 phillips bit fits perfect.
Most people do not know HOW to use the impact driver.
You must place the impact driver on the screw and push down and turn in the direction to loosen AT THE SAME TIME. Otherwise you must put a load on the screw THEN hit the driver with a small ball peen hammer.
Before you attempt o loosen the screw, just tap the stop of the screw with the small ball peen hammer to loosen the molecular bonding the screw has in the threads.