On Sun, 21 Jul 2013 00:17:16 -0600, Tony Hwang wrote:

Maybe plumber checks and clean pPtrap and snake the drain thru access
port.

I understand. But the OP didn't mention that so that's why
I had asked.

In "my" recent situation, for example, there was no p-trap
plug to remove; so I went through the outside 2" access pipe;
yet, to actually *snake* the kitchen drain, would have taken
a much smaller diameter than your typical snakes are, because
of the way a kitchen drain is designed (so that stuff doesn't
go down it, I guess).