Just bought a house it's 4 years old and the master bathroom tub has very little water pressure. I have already taken the cartridge out as the inspector said that it was an easy fix. Turns out that was not the problem it's a single handle unit delta 1400 series. I took off the spout and the water flowed through it just as slowly. I'm not sure where else to turn can anyone help?

Hot, cold or both?
Tub, shower or both?

Its tub and shower n water goes hot and cold just little to minimal pressure

Do you have an access hole on the other side of the wall? If so do you have stop valves?

No no access whole on other side of wall. Unfortunately

I assume water pressure in other parts of the house is normal.
Do you know what integral stops in a tub and shower valve are?

Yeah rest of house is fine and no I do not...

Integral stops are stop valves that are built into the body of the valve. One on each side for the incoming hot and cold water. The usually look like a big, slotted screw in the incoming pipe of the valve.

Remove handle and then remove escutcheon plate. With flash light look inside and see if there is any thing like that.

At this point I would guess (and it is only a guess) that previous owner had a leak and had cartridge replace, plumber turn off stop valves and forgot to turn back on.
Highly unlikely that you could have blockage in both hot and cold lines. If it were temperature balancing valve you would have cold even if you had not hot. Or you would have hot even if you had no cold.

Ok I think I know what u are talking about I will try in the morning here's a diagram I found from another user the valves are what is over each of the incoming pipes that was my next attempt once I saw the diagram

Thank you so much I will update tomorrow

If you have the integral shutoffs try spinning the stops to see if that fixes things. If that fails to resolve things then the entire stop can be removed and cleared of debris before reassembling (pulse water on with shutoff assembly removed)... should solve things nicely!

Mark