Rough start then Intake pop...

Maybe you guys can help me out. Yesterday my car started roughly and then a pop came from my intake(filter). I have no idea whats up with it. It sounded like a backfire in my intake. No one at the ORG has answered me, so maybe you guys will be of some help.
Thanks
Kevin

yup ur car is backfiring. i think u have fuel problem. maybe is one of ur injector. use a multimeter to check the ohm on the injectors and look up the spec. in the repair manual.

Thats kind of what I thought. It hasn't backfired since, but its still rough starting sometimes. My friend said is smelled funny when I started it tonight. I'll check it tomorrow. Also, Are there any codes that won't trip the CEL?
Kevin.