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My story with the P0440 code began a year ago. EVAP leak diagnosis was to replace my charcoal canister. This was done by Lexus, code came back. Then the fuel overfill check valve was replaced, again by the Lexus dealer, same code. We replaced the VSV valve under the hood, OEM gas cap x2 and every visible evap hose that we can see. Same code. Even the engine mounts and transmission mount were done to make sure the hoses were not coming loose due to movement. Same code. P0440.
Faint smell of gasoline near the drivers side rear fender persists but no visible leak anywhere. Lexus is stumped they can't figure it out, apparently they had 2 smoke machines on it and could not identify a leak anywhere. I am into this repair for ~3500$ and still the light comes on. The strange thing is, that as long as the fuel tank is over half full the light will never appear. Only when the tank gets to about 1/4 full will the check engine light illuminate.
Any help with solving this issue would be appreciated. If you had the same issue and were able to solve it let me know. My car is an 02 with 100K miles on it.
Did you have any damage to the driver's side rear? Maybe a fender bender?
Is the smell more evident from the outside or the inside? Any chance you smell it in your back seat?
Would you consider taking it to an independent Toyota mechanic? I think your best bet is to get someone under the car and see if they can smell where the gas smell is coming from. I think a good indy mechanic would be more willing to do that.
Most likely a broken hose. Pretty common. Do a slow detailed check of all vacuum hoses, touch and move them all.
report back with your finding please, this a common problem with many threads on the subject, here is a good one to look at… https://www.clublexus.com/forums/sc4...and-p0446.html
Did you have any damage to the driver's side rear? Maybe a fender bender?
Is the smell more evident from the outside or the inside? Any chance you smell it in your back seat?
Would you consider taking it to an independent Toyota mechanic? I think your best bet is to get someone under the car and see if they can smell where the gas smell is coming from. I think a good indy mechanic would be more willing to do that.
No damage to the vehicle, smell is outside mostly near drivers side rear. Car is otherwise in good shape and well maintained. Just this pesky problem that the dealer can't even figure out....so frustrating.
No damage to the vehicle, smell is outside mostly near drivers side rear. Car is otherwise in good shape and well maintained. Just this pesky problem that the dealer can't even figure out....so frustrating.
You have 2006-2010 wheels and taillights, please share a pic of the front
I think i found a solution to your problem…if correct, it is gonna be very $$$$.
see this thread, i found a video too. And yes, this is not an SC430 but Toyota likes to use similar designs on all models. https://www.clublexus.com/forums/gs-...ml#post9365605
Thanks for your replies and yes the tube that connects the gas tank to the filler pipe was replaced as well.The roll over check valve was replaced as well. That didn't solve it either.
What about the fuel cutoff valve or ORVR valve?
in post #6 above, i believe he replaced one of these, click the link and review that thread.
something is obviously leaking around the fuel tank.
my 2007 SC430 service manuals never address P0440.
Thanks again for the responses. Its a 2002 just with the updated front,rear and wheels. They tested the valves and they are working properly. I ordered the fuel tank to filler pipe hose from japan so that's next when I get it out storage. Currently its not being used....just a miserable experience so far with this issue. Otherwise the car is great. They don't make them like this anymore.
BGW, do you think the weight of the gas tank has anything to do with it? When it is full it hangs lower. When it is less, the tank applies less downward pressure opening the crack? Really seems like it should be opposite, unless the hose is connected on the bottom?
BGW, do you think the weight of the gas tank has anything to do with it? When it is full it hangs lower. When it is less, the tank applies less downward pressure opening the crack? Really seems like it should be opposite, unless the hose is connected on the bottom?
interesting theory and i like it…it is certainly possible.
the OP has thrown a bucket full of money at this issue (~$3500) and still not resolved.
The more i thought about it the more i realized there are usually three codes for a broken or detached vacuum hose in the engine compartment, P0440, P0441 and P0446.
P0440 alone is new to me and based on his experience, i hope it never happens to me.
since he smells raw fuel, i would be looking for the open source around the fuel tank. One guy said he found an open hose due to a rodent.
I sure hope the hose he ordered does the trick and i hope he comes back to let us know.
01-10-24, 11:21 AM
Help with P0440 code, experts please chime in.
