New Purchase - 2 Questions

I keep getting a Check Engine Light for my gas cap every time I fill the tank Code: P0440

It was cleared at the dealership but when I filled my tank after purchase the light came back on. Does anyone know how to fix this or how common it is?

Secondly, when I reach a speed of 65-70 MPH I sometimes get a soft shaking in the steering wheel...any thoughts?

Thanks in advance!

Check the seal on the gas cap, if it has cracks replace it. Beside that look around for any cracks in the EVAP lines under the hood and under the car. Aside from that, the most common problem I've found is the evap purge solenoid going bad.

The shaking sounds like tires out of balance.