After 12 years I replaced the sink on the bathroom pedestal, there was no prior drainage problem. Now the basin on the new sink fills after ~12 seconds. When I took apart the pedestal I also cleared the P-trap, extension pipe, and drain of hair, sludge, etc. I sawed about 1" of the the tail pipe on the new sink as it seemed to set a little low in the vertical pipe. Also, the drain pipe turns a quick right (close to 90 degrees) as soon as the horizontal pipe enters the wall. So I also sawed about 1" so the end of the horizontal so that it doesn't hit the back of the drain pipe. I don't think the sink stopper is set too low as the basin would fill immediately. Why is the basin filling and/slow draining? Any troubleshooting ideas will be greatly appreciated.