2
questions

Hi, I got the code C1391, which means there is a leak in the ABS actuator, Every time I clear the code the ABS work fine for 10 minutes then the lights come on again, No ABS, and breaks need more push.
I made the alignment at Tire Kingdom, and asked them to do the calibration of center steering, but nothing changed, recently I knew after changing some parts like the steering rack I have to do a calibration also for the yaw sensor.
I want to know is the actuator was damaged just after changing the steering rack? or it is a calibration matter? and do you know the exact steps for the calibration.
Thank you, I appreciate your help in advance.

I should be getting 30-43 mpg on the trips I take but not only get 24-26 mpg ??