I changed out the seat and the stem of the hot water, that was constantly running. That fixed the hot water valve problem but for some reason now when I turn on the shower water still comes out of the tub spout which decreases the pressure of the shower. Could I of ruined something when I changed out the hot water stem and seat? The nut was really hard to loosen. There are three faucets one for hot, one for the shower, and one for cold. There was no leaking out of the tub spout when the shower was in use before I changed out the seat and stem for the hot water.

Sounds like you might have cross threaded then seat when you installed it Is the water coming out of the spout hot or cold? Back to you, Tom

It has nothing to do with Hot water stem repair you have just completed. The problem is in your middle handle - the tub/shower diverter. There is a seat and washer as well. Take it out, replace washer and see if that helps.

While you are having the diverter stem out, inspect the large plastic washer located above the washer for cracks. See attached photo of Price Pfister diverter stem for better illustration...