Q: Getting various error codes

Sounds like you have several things going on. The first code P0220 is usually set because of a variance in voltage. This is sometimes due to a loose ground connection. A mechanic should be able to look up power and ground distribution locations and check the ground connections are clean and tight. The second code P0137 is an oxygen sensor code. This code is set when a lean condition is detected for an extended period of time. This can be caused by a vacuum leak or a faulty oxygen sensor. The last code P0446 is set when an EVAP vent issue is detected. A bad vent solenoid or faulty connection can trigger this code. None of these codes seem to be related to each other and are probably separate issues. Diagnosing these codes requires the use of specific diagnostic information, scan tools, and correct interpretation of the information collected. Consider giving YourMechanic a call to help you with diagnosing these codes.