I went to Autozone to pull a code and I got this code from them. P1491. It says it is the secondary switch solenoid circuit malfunction. What is this? How do I fix it? Does anyone have any information on this code?

 

P1491/0311 = Vacuum cut bypass valve or circiut fault.
It does not specify which "bypass valve solenoid" Vacuum operated are MAP, EGR and EVAP, check them out, these are generally on/off Solenoids.