Low pressure in faucet, not spray

[milotcat]

I have a Pegasus Kitchen faucet, dont know the model number. It is a single stem with control bar and sray attachment. Pressure is getting lower and lower from the stem but spray is fine. I took off the aerator, but the pressure remains the same. Any ideas?
Someone told me there is a spring that may be bad. Is this a difficult job? As u can see, I'm not very plumbing-wise, but will try anything, unless i would make problem worse.

[Redwood]

It may be the diverter that is causing the problem.
Do you have the original paperwork that came with the faucet?
It is a Home Depot House Brand and all roads in research lead to Home Depot. These most often are Chinese faucets and without the original paperwork figuring out exactly which part number you need can be fun.

Personally I would rip it out and install a Delta or, Moen faucet in its place.

You can talk to smockman at 1-888-328-2383. Maybe you will get lucky and talk to someone there that can help you.