I have recently replaced the sink and faucet in the main bathroom. The problem I am having is that I have now lost pressure to the kitchen sink on the same floor. I have checked to make sure the main water supply valve is on all the way and have checked for leaks all along the water line. I have found no problems.

have you tried cleaning the screen in the sink you may have loosened some meneral in the pipes. if this don't help you may have to look deeper in your faucets
hope it works out.