Kitchen sink water pressure...

[TMan59]

So it seems our kitchen sink water pressure seems low. Both hot and cold. Shower and bathroom sink are fine.
So, we thought we would replace the faucet, maybe it was clogged or something.
Then one day as I am brushing my teeth in the bathroom, she turns on the kitchen faucet and says it has plenty of pressure when I had the bathroom faucet on.

Ok, so whats going on here?
Any ideas?

[BFlinn181]

If you have a filter on the kitchen cold water line, turning both hot and cold faucets on in the bathroom could allow extra flow through the lines increasing flow in the kitchen. I'd replace kitchen filter and also remove and clean out the aerators in kitchen and bathroom. I think you'll find flow increases.

[TMan59]

Thank you.
We have replaced the filter under the sink twice, and cleaned the faucet in the kitchen. Bought new pressure regulator.
Just wondering if anyone else has faced this?