2002 sc430 fault codes p0440 p0441 p0446.

[Jeff1104]

Replaced knock sensors, no check engine light for couple weeks now engine light on getting P0440,P0441,P0446 codes..checked gas cap,purge valve? Where is it?..any suggestions where to go with this would be appreciated 

[Jeff1104]

Found it top left side on intake

[RX400h]

And with an LS430:

Check engine Light on with three codes P0440, P0441, P0446 on my neighbors 2002 Lexus Ls430. I did a little research and (justanswer.com)