Folks, I have read multiple threads on P0440 and P0446 on the forum. Just wanted to share that these started appearing on my 2000 Rx300 sometime after I changed my cabin and engine filters. I thought that the filters were not installed correctly so I rechecked them and they both seem to fit snuggly. Any ideas about what path I can take for further investigation.

I am going through the below thread but was wondering if any of you noticed these codes after filter change and have any specific suggestion to address those. Any pointers are appreciated. Thanks!
check engine code PO 440 PO 446 - ClubLexus - Lexus Forum Discussion

 

Check the hose connected to the backside of the engine air filter box
https://www.clublexus.com/forums/rx-...l#post11346991

 

Yep, what he said.^^^^^^^^

 

Thirding; that's exactly what mine was with the P0446 code, and it makes perfect sense since you were just in that area moving things around. You can either just put it back with a hose clamp, or swing by a local parts store and grab a section of vacuum hose if you want nice, new, supple hose there. I opted for that; old girl deserved a little something new. Lol.