Backfire through intake?

[jhandy]

Hello,
My car has done this from new, however it is happing more recently. Sometimes when I first start the car for the day, it will make a popping sound, like a burp or backfire, from the intake. Just one or too pops.
The car has been de-snorkeled, but retains the original air box.
Car seems to run fine otherwise, one time a CEL came on and blinked and then went off never to return. I took it to the dealer and they said that the computer does not have any error codes.

Any thoughts?

Thanks,
James