Small hole in AIR INTAKE! could this be my hesitation prob?

[Dweezle]

Well i dropped into MANIA this arvo, They had a quick look and said that it didn't seem to bad. That is is prob something else. That was all i got out of them. So still at square one.
I replaced the Oxygen sensor a few months ago, when i first got the car, i had a chronic idle drop. fixed it right up.
But i am wondering if maybe i disturbed the wire when i was setting the timing a month or so ago. Will check that tomorrow.
Could that cause a similar thing?
I might just unplug the sensor and see if it changes or stays the same. That would let me know if its working or not, wouldn't it??
Otherwise ill find a Multimeter about and get right in there

Thanks for the help though guys, its leading me in directions i wouldn't have looked at. MUCH APPRECIATED