Please excuse any rambling. This is my first post. A check engine light came on in my 2002 LS 430 with 170k miles. It showed an error with the knock sensor bank 1. The mechanic I use is generally very good, but not Lexus trained. He replaced both knock sensors, but after about an hour of driving, the check engine light re appeared and showed knock sensors bank 2. I also have shown codes PO 440 and PO441. Can anyone tell me what could be the root of this problem? I have owned this car since 2016 and it has been a dream. Regular maintenance has always been preformed.
Any suggestions would be greatly appreciated. Also, should the starter be changed while the intake is off? The starter has shown no problems to date.

 

EVAP errors - here is a YT Video - -