The P0441 Thread
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Any one know the Toyota part numbers for the vacuum hoses on the evaporator system? I replaced my fuel filter last week and then the code hit today. Gas cap is new and so is the solenoid on the top of the engine. Looked at my hoses and they have seen better days. Thinking that might be it.
prwillard2
SILVER Star
Got this code today at around 7000 feet while driving across Wyoming towing a 6000 pound trailer.
I've got an LRA 12.5gal Aux Tank.
I drove another 50ish miles to my destination, and cleared the code. I hope that wasn't a dumb decision.
I've had my tank for about 6 months now, but this is the first time I've experienced gas boiling, fuel vapor smell in the cabin, or gotten this code.
It's been over 100+ degrees as I've driven up through Utah to Salt Lake to now Rawlings, Wyoming on our way to Denver. Believe it's probably the heat from the exhaust and ambient air temps boiling the fuel in the aux tank that caused all this.
Hoping I didn't cause any lasting issues.
I've got an LRA 12.5gal Aux Tank.
I drove another 50ish miles to my destination, and cleared the code. I hope that wasn't a dumb decision.
I've had my tank for about 6 months now, but this is the first time I've experienced gas boiling, fuel vapor smell in the cabin, or gotten this code.
It's been over 100+ degrees as I've driven up through Utah to Salt Lake to now Rawlings, Wyoming on our way to Denver. Believe it's probably the heat from the exhaust and ambient air temps boiling the fuel in the aux tank that caused all this.
Hoping I didn't cause any lasting issues.
The lower vapor pressure (at altitude) also contributes iirc with this boiling. I never smelled fuel, but my charcoal canister was toast nonetheless. I cleared my code a couple times to make sure it was real. I also started the process of buying a new cc when the next parts sale came around to replace it.
prwillard2
SILVER Star
Can you share the charcoal canister part number? I've got another 3000 miles of driving so I'm riding this thing hard for the next two weeks moving cross country.
Do you have to drop the tanks to get to the charcoal canister?
77740-60520 for the charcoal canister. I’m assuming the part hasn’t been updated. You’ll get the annoying CEL consistently if it’s your cc. Keep your reader handy to clear it and keep your cruise control functional.
You have to drop your aux tank to get to the charcoal canister unfortunately. If it weren’t for that, all you’d need to do is drop your spare.
Edit: I haven’t tried it, but someone else said the Corolla charcoal canister would work too. 77740-02131 or 77740-02130 are the part numbers for this wildcard supposedly. *Use caution with this gamble*
prwillard2
SILVER Star
Drove about 300 miles today down from Wyoming to Denver. Had a terrible time filling before the start of the trip in Wyoming, pump kept clicking off constantly, but with my main tank reading half full I put about 10 gallons in slowly.
Smelled gas at the end of the trip, but no CEL came on.
Also trying to only use ethanol free fuel, if that helps at all.
not reassuring about the pump clicking off. I don’t know what to offer there for troubleshooting.
I’m also not smart enough to try and explain any (likely negligible) vapor pressure differences in the ethanol containing vs etoh free gasoline. I’d imagine your ethanol free choice would be a good decision just based on all the issues ethanol can cause. It’d be cool if the fuel in your charcoal canister would evaporate eventually and you’d be code free. I don’t know that this is going to happen though.
I had my CC (and cc filter) replaced at 175k in Oct 2025 when I had all 5 codes and a gas smell in the cabin in mountain passes. New gas cap in April 2026, about 184k when p0441 popped back up twice after cruise Moab. No issues for 2 months and then got p0441 a couple times followed by the other codes when I was in UT/CO last 2 weeks. Codes are cleared but permanent, going to see if they disappear now that I’m at 600’ above sea level again, if not NFC what to do next since my canister is new
Anyone with more experience than me using the test modes in techstream want to swag what’s wrong? The charcoal canister and filter are only 13k miles old so while they certainly could have failed again that seems awfully unlikely right? Right?
Yikes. Were your lines clear of fuel? If this is correct, I’m guessing you may have had gas that overwhelmed your charcoal canister again. But again, this is a guess without knowing specifics.
I definitely had boiling fuel on the last trip. Towing but no off-roading. Got a p0441 first once or twice, followed by the litany of other codes going forward.
I just joined the P0441 club today, yay I guess. We’ve been in the Idaho mountains and cooler temps for about a week now and my last full up was in a much cooler area. Came down south of Boise and it’s 100°, slight fuel smell as it’s gotten hotter. Reading through this thread I’m pretty sure it’s temp related but just to be sure I figured I’d post here for feedback.
Truck at 53ish thousand miles, 40LRA and just changed that LRA filter before this trip. I cleared the codes in the parking lot and will eat dinner. We’ve been in the car all day driving all around but haven’t shut it off until we stopped at a place to eat. We couldn’t eat there so jumped right back in and fired it up, 30 seconds the CEL and dash message hit.
We’ll be home next week but have about 2500 miles left on this trip but I’m probably done with any 4LO stuff. Fortunately, I’m somewhat of a parts hoarder so and I already have the canisters at home if I need to replace them…I’ll cross that bridge once I get home.
For now, it sounds like I’m good to go, just keep clearing any codes if they keep popping up and just drive like normal… this sound about right?
Truck at 53ish thousand miles, 40LRA and just changed that LRA filter before this trip. I cleared the codes in the parking lot and will eat dinner. We’ve been in the car all day driving all around but haven’t shut it off until we stopped at a place to eat. We couldn’t eat there so jumped right back in and fired it up, 30 seconds the CEL and dash message hit.
We’ll be home next week but have about 2500 miles left on this trip but I’m probably done with any 4LO stuff. Fortunately, I’m somewhat of a parts hoarder so and I already have the canisters at home if I need to replace them…I’ll cross that bridge once I get home.
For now, it sounds like I’m good to go, just keep clearing any codes if they keep popping up and just drive like normal… this sound about right?
Clearing codes will get you going, even if you need to get in and out of 4Lo.
in the meantime check your gas cap, make sure it’s tightening correctly, and clean the seal. My recent issues started with p0441 and after 2 cycles other codes appeared, so maybe there’s a chance the gas cap has failed. My gut says it’s not an expensive fix until you get all 5 other codes…
in the meantime check your gas cap, make sure it’s tightening correctly, and clean the seal. My recent issues started with p0441 and after 2 cycles other codes appeared, so maybe there’s a chance the gas cap has failed. My gut says it’s not an expensive fix until you get all 5 other codes…
Ok, cool. I’m actually at the gas pump now stuffing 60 gallons in killing time on mud… I’ll check the cap now. The gas cap compartment is super dusty and there is dust on the gas cap o-ring but there is a solid black line depicting a seal… I’ll clean it all up regardless and keep an eye on things.
What I learned the last time I had a vacuum code: These are not parts cannon problems, every one is different, and you need to do the diagnostics. A smoke tester is essential for me.
That said, anyone with a LRA should definitely make sure you've done the vent mods, and your vent filter is clean.
We suffered the venting vapor/fuel and hard to fill issues when our LRA vent filter (well, it was a prefilter that we added) was dust clogged.
I always carry a basic code reader in the 200.
Also, not directly related, but when the stock charcoal canister on our current 80 failed, it had similar pressure, fume, gas spewing, elevation exacerbated issues.
That said, anyone with a LRA should definitely make sure you've done the vent mods, and your vent filter is clean.
We suffered the venting vapor/fuel and hard to fill issues when our LRA vent filter (well, it was a prefilter that we added) was dust clogged.
I always carry a basic code reader in the 200.
Also, not directly related, but when the stock charcoal canister on our current 80 failed, it had similar pressure, fume, gas spewing, elevation exacerbated issues.
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When I see these codes my thought is typically “bad canister”. But for comparison I replaced my gas cap in Sept 2025, then ultimately my charcoal canister was replaced 10/17/25 and my issues went away after that. I got the same codes after Moab in April this year after having fuel boiling, swapped the gas cap because it wasn’t clicking down right (again), and then no codes for 2 months until my long trip in June. During that trip fuel boiled and now my gas cap doesn’t click correctly. Just swapped it again and I’m watching for the full set of 5 or 6 p043e, 043f, 2701, p0441, etc codes before I go down the canister route because even with a few days of off-roading and some towing there’s zero reason the Toyota replacement part should’ve lasted 7 months and less than 10k miles.
TBH I’m leaning towards going full parts cannon on the VSVs etc before doing the canister again because in my case at 188k miles I sure feel like something else is causing the canister to fail. But I also have a theory that fuel boil, the relief mechanism on the gas cap opens up, but then it breaks or sticks and causes a lot more boiling which then fouls the canister, given each time I’ve had this my gas cap no longer clicks “early” and instead either clicks at the very end of tightening or doesn’t click at all anymore.
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If you've got a higher end OBDII programmer or techstream, you can cycle your VSV's via a test cycle the vapor recovery bits can run. It will (hopefully) lead you away from a straight parts cannon approach, but can help you dial on what is or isn't malfunctioning and causing codes.
Yep Techstream shows everything working as best I can tell, but I still get the series of codes every few days.