What causes these codes? P0440, P0441, P0446
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I just received p0440, p0441, and p0446 codes again, and the VSC, Trac off, and check engine lights are on. I have cleared the codes and they stay off for several days/weeks and several hundred miles. I believe they have to do with the emission control module (according to Auto Zone), but I don't know what to do to keep them off. I have been very careful to only fill the gas tank to the automatic shutoff and add no extra gas, and to screw the gas cap on tightly, usually tightening the cap into the clicking noise three times. I have a CD service manual, but cannot find these codes in the manual. Can anyone give me additional things to check and fix. Thanks in advance for your help.
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P0440- Evaporative Emission Control System Malfunction
(caused by the fuel trank pressure being equivalent to atmospheric pressure after 20 minutes with vehicle on)
Areas to check:
Vapor pressure sensor
fuel cap
vacuum hose
fuel tank
charcoal canister
P0441 Evaporative Emission Control System, Incorrect Purge Flow
P0446 " Vent Control Malfunction
these 2 codes usually accompany the P0440 and they have similar trouble areas
(caused by the fuel trank pressure being equivalent to atmospheric pressure after 20 minutes with vehicle on)
Areas to check:
Vapor pressure sensor
fuel cap
vacuum hose
fuel tank
charcoal canister
P0441 Evaporative Emission Control System, Incorrect Purge Flow
P0446 " Vent Control Malfunction
these 2 codes usually accompany the P0440 and they have similar trouble areas
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getitright (09-23-22)
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I just received p0440, p0441, and p0446 codes again, and the VSC, Trac off, and check engine lights are on. I have cleared the codes and they stay off for several days/weeks and several hundred miles. I believe they have to do with the emission control module (according to Auto Zone), but I don't know what to do to keep them off. I have been very careful to only fill the gas tank to the automatic shutoff and add no extra gas, and to screw the gas cap on tightly, usually tightening the cap into the clicking noise three times. I have a CD service manual, but cannot find these codes in the manual. Can anyone give me additional things to check and fix. Thanks in advance for your help.
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LegoGuy (04-10-17)
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Me toooo!
If this works I owe you guys big time! ![Big Grin](https://www.clublexus.com/forums/images/smilies/biggrin.gif)
SO I reconnected the hose then I disconnected the battery for a bit and will reconnect later. I've heard that's a good thing to do what getting your codes reset. Yes? No?
Does this sound like the proper steps to take getting things set back to normal, if in fact this was the only problem?
Thanks in advance! The info on this site is outstanding!
![EEK!](https://www.clublexus.com/forums/images/smilies/eek1.gif)
![Big Grin](https://www.clublexus.com/forums/images/smilies/biggrin.gif)
SO I reconnected the hose then I disconnected the battery for a bit and will reconnect later. I've heard that's a good thing to do what getting your codes reset. Yes? No?
Does this sound like the proper steps to take getting things set back to normal, if in fact this was the only problem?
Thanks in advance! The info on this site is outstanding!
![Woot](https://www.clublexus.com/forums/images/smilies/woot.gif)
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Hello,
It could be oxygen sensor(s) need to be replace.
you can get this replacement part(s) thru online autopart stores.
It cost about $ 120-145.00 including shipping & handling and the oxygen sensor is located under the driverside seat, you may have to use sharp blade to cut carpet to access and follow the wire(4wires cable wrap around black tube) to outside of the car.
Good Luck!
*p.s. after replacing with new oxygen sensor you have to reset the mother board computer on a car, It will be go out buy one of the CanOBD2 CodeReader made by Innova, It is really worth the money. It costs about $ 100-150.00 depend on autoparts store or look for sales like kragens auto part.
Good Luck again,
Bruce
It could be oxygen sensor(s) need to be replace.
you can get this replacement part(s) thru online autopart stores.
It cost about $ 120-145.00 including shipping & handling and the oxygen sensor is located under the driverside seat, you may have to use sharp blade to cut carpet to access and follow the wire(4wires cable wrap around black tube) to outside of the car.
Good Luck!
*p.s. after replacing with new oxygen sensor you have to reset the mother board computer on a car, It will be go out buy one of the CanOBD2 CodeReader made by Innova, It is really worth the money. It costs about $ 100-150.00 depend on autoparts store or look for sales like kragens auto part.
Good Luck again,
Bruce
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Did it work for you? My car also just threw the Check engine, vsc, and trac off. I'll be heading to autozone today to pull the code. Hopefully, it's the same reconnect the hose and disconnect the battery for a while then reconnect up.
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I'm having this same issue. Also, I noticed that my car sounds like it's going to completely shut off. I took my IS300 to the dealer, and they said I had a weak battery. So I replaced it and when I was heading home, it sounded like it was going to stall. I went back and the diagnostics read P0440, P0441, and P0446. The check engine light is on, and Trac Off light is blinking. I'll check the hose and see if that works. Thank you!