Hiya's; my sink water pressure became low a few monts ago, the sprayer seems to work fine along with the rest of the faucets in the house. This is a new faucet I bought a year ago than this started happening. Both hot and cold have decreased drastically but the rest of house is fine.
The turn off valve(s) may be the culprit. If old, they can have mineral deposits which can break loose when closing/opening and cause partial blockage. Turn off main water and remove valve stem. Place towels/pans to catch water and turn on main water momentarily to flush line. Reassemble valve and remove aerator and flush entire line. Hope this works.