Check P-trap connections (tighten if loose). Replace worn-out washers or O-rings. Reapply plumber’s tape on threaded fittings.

Causes: Bacteria buildup, rotting food (kitchen sink), or a dry P-trap.

Fix: Clean the drain, flush with baking soda/vinegar, or run water to refill the P-trap.

Drop-in (self-rimming) sinks are the simplest because they sit on top of the counter with minimal adjustments needed.