Helppppp please
 

ok so got a error code P0087 says low fuel rail pressure so I changed the pump in the back of the seats lights still on saying the same code bought a regulator can't find it on the car is it on the pump or the fuel line anybody have this code before and if so what's the fix?

It's a 2012 sonata gls 2.4l

First thing I would do is write the code down then proceed to erase it
Wait to see if it comes back.
If it doesn't come back then ignore it
If it does come back then go about check for fuel pressure
Does it match the diagnostic trouble code?
If not then sensor is faulty
If it is then would check fuel pump or regulator
Also check to see if fuel relay is working properly

Good luck