a/c runs cold then a slight smell comes from vent, air gets warm, i shut a/c of wait a bit then a/c gets cold again, does this all the time,, notice an oily residue on the vents

Take your car to an authorized service center, Honda or otherwise, that can determine if it is coolant or a/c compressor oil that's coming through the vents

Your evaporator is not draining properly so moisture is building up and causing the smell. If oil was leaking out your A/C wouldnt even work and coolant passes threw the cabin when the heat is on. Also replace your cabin filter if you have one.

Not saying I'm right but what's the oily substance? Hey tom demyan, what do you think? I shouldn't be sitting in front of the computer , bleary eyed at times, thinking cap askew. LOL!