1996 Pontiac Grand Am OBD CODE

1996 Pontiac Grand Am 4 cyl Automatic 186 miles

Ive been having issues starting my car on the first try. When I am at a complete stop, the car jerks as if its going to die on me. When I am driving and easing up on the gas, the car jerks. So I went to an auto repair store to see what obd codes come up because the check engine light came on. The code was p0172 system too rich (bank1). What does that mean?
Another issue I have noticed was everytime I am pressing on the gas and have the a/c on, I hear a very loud rattleing noise. But as soon and I turn the a/c off, the noise is gone.