I'm getting P0440, P0441 and P0446 after installing HPS cold air intake and cat back exhaust. I disconnected negative terminal when installing everything, AFTER searching the forum I read that these codes can pop up if the EGR hose isn't connected, so I triple checked my connections and still am getting a light about every 7 days after I clear the code. Any thoughts....

 

Do you have a 2GS3 or 2GS4? On my '99 GS400 these hoses were causing my P0441/P0446 codes. They were brittle and cracking. You may have to lift the engine cover to get to them.

 

Sorry, I should have mentioned its a 2001 GS430

 

You were exactly right Kevin! Thanks so much for your help!!!

 

Great! Glad you found it.

 

Got these same three codes tonight on my 2001 GS430. Will start by checking those hoses. Thanks.

 

Turned out to be a simple fix for me (vapor line disconnected) - top of engine towards driver side.

It’s the exact lines pictured above. All three codes are history (P0440, P0441 and P0446).