I recently install a new bathroom sink/vanity. The drain pipe was 1-1/4" and I wanted to have a clean out at the bottom on the trap. The problem is that none of the hardware stores that I go to had 1-1/4" trap with a clean only 1-1/2" so I use and 1-1/2" and went down to 1-1/4" before the drain goes behind the wall. Now when the sink is filled it doesn't drain right. Do you think by doing this I caused the issue or could there be another issue.