Is your kitchen drain always leaking? The problem might not be the drain pipe at all.

A while ago, I took a kitchen repair job where the homeowner said there was a constant leak under the sink. At first, he thought the drain pipe was aging, so he went to Home Depot, bought a new P-Trap assembly, and replaced it himself. As it turned out, it still leaked after the replacement. In fact, it leaked even worse. When I first arrived at the site, the bottom panel of the cabinet was…