We just put in a new Moen faucet yesterday. It was doing fine for 24 hours. The pressure was slightly lower than before but not that big of a difference. Now, it all of a sudden is hardly coming out. It's not the aerator. I took that off and the pressure still is awful. What could have changed so drastically in 24 hours?

If there us a sprayer there is a part called a diverter. If that gets plugged you will have little to no pressure. If you have hard water a water filter might not be a bad idea. I've had this same problem and had to replace the faucet. I put in one without the sprayer and have had no problems.

Your inlets are likely clogged. A Moen has cartridges which can be removed and cleaned, no need to replace the faucet. Which model did you install?

Adler CA87554C. I took out the diverter and it had black pieces clogging it so I cleaned it out. The cold water pressure is back to normal but not the hot. What could that be?

So the faucets w/o sprayers don't have a diverter? Mine does have the sprayer. I took out the diverter and it had black pieces clogging it so I cleaned it out. The cold water pressure is back to normal but not the hot. What could that be?

There is a black piece that I removed also and under it, the hole for the hot water flow was clogged w/ debris that I didn't see before. Moen walked me through it and they said turning the valves on/off can stir up debris. Everything is cleaned and running free of debris. The water pressure is back to normal!

Here is a diagram of your faucet. http://www.moen.com/shared/pdf/ca87554pt.pdf Both parts 885 and 886 need to be cleaned well. You can also get free replacement parts from the Moen website