I changed the water main shut value and now I have low water pressure, I also made sure that the arrow on the value was going in the direction of the water flow

Hello gbrlgmz

Just to make sure : did you check the valve itself before - and did you open the valve completely after - the installation ?

:)

yes I checked the value and saw the stop open and close, I also closed the value and opened it like 20 time lol but I think your right I should just go buy an other one and check it that way

Compare the port size on the valves too. The port size is the size of the opening inside of the valve... not the thread size. Some valves are made with a dramatically reduced port. If you can find one, get full port. That means that if you have 3/4 threads, that the valve is 3/4 all of the way through.

It is also possible that when you turned the valve back on that the water coming into the house caused scale and sediment to break loose. That sediment may be blocking your pipes some place or is probably caught in your faucet aerators. Check and clean all of your faucet aerators. If they have scale build up, you can soak them in vinegar for a while.
Al