With the P-trap removed, you have direct access to the drain line entering the wall (the trap arm). If you suspect the clog is further down, this is your chance to clear it. Insert the head of a small drain snake (or hand auger) into the pipe. Push the cable in until you feel resistance, which is likely the clog. Tighten the locking screw on the auger's handle and begin turning the crank clockwise while applying gentle forward pressure. You'll feel the snake working its way through the grease. Once the resistance lessens, you have likely broken through. Retract the snake, wiping the cable with a rag as you pull it out to minimize mess.
Step 4/5
Snake the Drain Line2 min