I am having a problem attaching an ipone 4s and weather flow system to the phantom 4. When I fly it will drift and not lower unless in sport mode any settings I could change or help. Thanks,

It will also shake hard then fall a little

Well the reason would be it's too much weight. You need to reduce the weight to make it controllable

You've blocked the downward visual position hold sensors and ultrasonic height sensors under the aircraft!
Never pull the throttle full down with it like that - it will turn the power off!

You could try turning vision sensors off, but it would be better to move your equipment to where they wont cause a problem, maybe on the outside of the legs, preferably the front legs...

I could try on the front because I need to see the phone but balence would be off could it be the weight or no. Cannot reduce the weght.

X-ACTO! Posted at 2017-9-28 14:42
I could try on the front because I need to see the phone but balence would be off could it be the weight or no. Cannot reduce the weght.

You haven't said how much weight you are adding.   

I would try and keep the extra weight under each propeller below 100g, 150g will start to cause problems.  It doesn't need to be perfectly balanced but distributing the extra weight on both sides would be sensible.

You must not block the ultrasonic sensors, and that means nothing mounted between the legs unless it is forward of the gimbal.  Gimbal guards sometimes result in crashes because the ultrasonic sensors mistake them for the ground.

Just under a pound

In fact, we don't suggest attaching any part to the drone to fly. For your case, please unload the phone and weather flow system and test again to see if the drone performs properly. If everything works right, then it is the problem of the payload, if it also shakes, you need to calibrate the IMU.

It works fine without