The P0441 Thread (1 Viewer)

[bemerritt]

Smelling gas, gas vapors out the fill up tube and error codes. Seems to be fairly common amongst the 200 series when in 4lo, at high altitude and with high temps. Sometimes with only one or two of those contributors.

I finally got my first code, P0441 this past weekend. It was rather annoying as I initially didn't clear it so i could do more research on it before clearing it, but that did not allow me to shift out of 4lo back into 4hi.

I know many have had similiar issues but didn't see too much of a dedicated thread to this code. So with that I ask, what are you all doing when getting it? Clearly having a reader that can clear it if you have it out on the trail is a must, because if you cant shift out of 4lo, you can't get home.

But once home, what are the best steps forward? Just clear it when it comes or take it to the dealer and pay the piper? Seems like it is related to EVAP system, is it easily handled in the driveway by a somewhat competent wrench turner?

Thanks for all of the wisdom and hopefully this will help others in the future. If i didn't have a way to clear the code it would have ruined the trip.

 

[bronc076]

When you fill your tank do you keep adding fuel after the pump clicks off? I'd clear it and hope it does not come back. One can flood the charcoal canister by continuously overfilling the tank.

This is a good description the system.

Evaporative Emission Control (EVAP) System - P0441 Diagnostic Code - Trouble Code Diagnosis Guide | Toyota Parts Center - https://parts.olathetoyota.com/p0441-code-toyota

 

[bemerritt]

I do not, although at 10 mpg with 35's i really should, as a 200 mile range is garbage. I was at about a half tank or so when this happened, which makes it a little surprising.

Thanks for the link, i'll read up.

 

[karthurbry]

Dealing with the same issue. I replaced the old fairly degraded gas cap with a Toyota unit, disconnected the battery for a bit and the error cleared....but it has come back! I've read there is a evap canister purge valve that can be the problem but I fear it is above the gas tank. Keep us posted on your findings and I'll do the same!

 

[bronc076]

South Main Auto on YouTube does a really good job of explaining how things work. I've seen several videos where he explains evaporative emission system operations and troubleshoots faults. Here is a video, it's on a Buick but most of these systems work the same way or similarly.



hope this helps.

 

[TeCKis300]

P0441 as documented - Evaporative Emission Control (EVAP) System Incorrect Purge Flow.

That is the airflow from the fuel tank sub-system to the intake of the engine is out of range. Normally, this flow is turned on by the ECM at intervals, to re-charge the charcoal canister, by drawing fuel vapors into the intake and burned off. So this airflow has a typical and expected fuel vapor vs oxygen composition.

Out of range can be in one of two ways.

There is too much airflow (aka oxygen) coming into the air intake via possibly an atmospheric leak in the fuel subsystem...something like a loose gas cap.
-or-
Too little airflow (stuck purge valve) or too much fuel (fuel boiling) coming into the air intake.

The ECM can know this in closed loop via the oxygen sensors in the exhaust showing it's either too rich, too lean, or no change when opening the purge valve. These symptoms can be caused by a faulty purge valve itself, if it never opens. Or possibly a tangential issue with something like the PCV.

If this is happening in Colorado, we know fuel boils in these extreme conditions. This would cause the purge flow to be hugely rich (lots of fuel). Easily outside the expectations of the ECM, hence the code.

Resetting the code outside of the conditions should solve the problem, unless the high pressure condition damaged something like the gas cap, fuel VSVs, or charcoal canister.

I echo others that it's really important to carry a OBD-II reader on the car as a basic tool as I've been caught in these situations too. Another workaround is to reset the computer by pulling the negative terminal off the batt for a couple minutes.

If it is the purge VSV, it's at the top of the engine and easy to reach. I doubt it's that however.

 

[karthurbry]

This is great info. Thanks everyone!

 

[Adventureguy]

P0441 as documented - Evaporative Emission Control (EVAP) System Incorrect Purge Flow.

That is the airflow from the fuel tank sub-system to the intake of the engine is out of range. Normally, this flow is turned on by the ECM at intervals, to re-charge the charcoal canister, by drawing fuel vapors into the intake and burned off. So this airflow has a typical and expected fuel vapor vs oxygen composition.

Out of range can be in one of two ways.

There is too much airflow (aka oxygen) coming into the air intake via possibly an atmospheric leak in the fuel subsystem...something like a loose gas cap.
-or-
Too little airflow (stuck purge valve) or too much fuel (fuel boiling) coming into the air intake.

The ECM can know this in closed loop via the oxygen sensors in the exhaust showing it's either too rich, too lean, or no change when opening the purge valve. These symptoms can be caused by a faulty purge valve itself, if it never opens. Or possibly a tangential issue with something like the PCV.

If this is happening in Colorado, we know fuel boils in these extreme conditions. This would cause the purge flow to be hugely rich (lots of fuel). Easily outside the expectations of the ECM, hence the code.

Resetting the code outside of the conditions should solve the problem, unless the high pressure condition damaged something like the gas cap, fuel VSVs, or charcoal canister.

I echo others that it's really important to carry a OBD-II reader on the car as a basic tool as I've been caught in these situations too. Another workaround is to reset the computer by pulling the negative terminal off the batt for a couple minutes.

If it is the purge VSV, it's at the top of the engine and easy to reach. I doubt it's that however.
View attachment 3072074

Hey there I have a ‘21 200 series with a LRA 40 aux fuel tank. Been getting multiple CEL’s with the P0441 purge valve code. Also have a pretty strong fuel smell in the cabin. So far I’ve gone through 2 charcoal canisters and my installer has tried multiple remedies at LRA’s direction. Is the solution to just clear the CEL code with a scanner? Will this protect the charcoal canister? And do I just have to live with the fuel smell?

 

[TeCKis300]

Hey there I have a ‘21 200 series with a LRA 40 aux fuel tank. Been getting multiple CEL’s with the P0441 purge valve code. Also have a pretty strong fuel smell in the cabin. So far I’ve gone through 2 charcoal canisters and my installer has tried multiple remedies at LRA’s direction. Is the solution to just clear the CEL code with a scanner? Will this protect the charcoal canister? And do I just have to live with the fuel smell?

Hard to say. Is this happening regularly or on trips? Perhaps at elevation? What other mods do you have particular in bumpers and skids?

 

[Adventureguy]

Hard to say. Is this happening regularly or on trips? Perhaps at elevation? What other mods do you have particular in bumpers and skids?

I have full skids and front and rear bumpers. On 34” tires, regeared. First began on a trip to Colorado but I was still in Georgia when the CEL came on. It’s still regularly trips the check engine light when just driving around Georgia and I have a constant fuel smell when driving. It’s atrocious

 

[TeCKis300]

I have full skids and front and rear bumpers. On 34” tires, regeared. First began on a trip to Colorado but I was still in Georgia when the CEL came on. It’s still regularly trips the check engine light when just driving around Georgia and I have a constant fuel smell when driving. It’s atrocious

What bumpers and skids?

Would it be correct to say that the fuel smells are more likely to come with extended driving? Or is this all the time even parked in the garage?

 

[linuxgod]

@Adventureguy, Constant fuel smell combined with a code that keeps coming back makes me suspect you have a vapor leak. The fact you have an aux fuel tank pretty much seals that theory for me. Not sure when your LRA tank was installed but if it’s recent I’d go back to the installer

 

[Adventureguy]

What bumpers and skids?

Would it be correct to say that the fuel smells are more likely to come with extended driving? Or is this all the time even parked in the garage?

ARB front and rear bumpers. Bud built full steel plates. Fuel smell both when driving and when in the garage. It does seem to be intermittent. Much worse when the tanks are full but still smells sometimes even when tanks are at half capacity.

 

[TeCKis300]

ARB front and rear bumpers. Bud built full steel plates. Fuel smell both when driving and when in the garage. It does seem to be intermittent. Much worse when the tanks are full but still smells sometimes even when tanks are at half capacity.

There's several different types of issues and trying to help isolate what it could be. There could be several contributing issues as well.

Do you ever get P0455 large EVAP leak or P0456 small EVAP leak codes? That would generally rule out a leak as a result of plumbing issues if you don't see these.

If you get smells in the garage (when car is cold), that could suggest that your charcoal canister breather is not located high enough and fuel vapors (being heavier than air) leak out.

If you're getting more fuel smells on longer trips or after returning from trips and parking, could suggest that it's more due to a fuel heating issue as a result of armor and LRA where vapor pressure are higher than can be contained.

DIY Fuel Heating/Boiling Mitigation

This thread is not quite a comprehensive fix (yet), but hopefully gets the ball rolling to improve upon fuel venting/boiling in the 200-series. I don't have all the answers and hoping there will be continued contributions by the hive mind. This is one of those issues that may not have a single...

forum.ih8mud.com

 

[18Cruiser]

Just a point of reference. I got the P0441 Touble code on my way back from Colorado on the highway in the Texas oven but first smelled the gas while doing some trails near Breckenridge.

Eventually the code cleared itself and since I was in 4Hi it didn't matter really, I had a scan tool at the house (which I will carry with me from now on as basic stuff I carry) but I didn't clear it because I wanted a mechanic to look at it.

Once in Dallas, as I stated the code had cleared itself, the mechanic could not tell any damage and said just roll with it unless it keeps coming back. He checked the cannister and the gas cap but found no issues.

I posted a thread if anyone wants to see the discussion there.

18Cruiser

forum.ih8mud.com

 

[acruisinf]

Hi team - this gremlin came up for me this morning driving the kids to school.
4LO flashing, CEL, TRAC OFF. Pulled code P0441 confirmed.
2015 with ~103k. Been noticing fuel smell on start up lately.

I have a reader and can clear the code, but would like to fix the root cause if possible. Any advice? New gas cap as a minimum?

TIA!!

 

[MCtree]

I’m on a road trip and just got this P0441 code.
I cleared it once but it came back after I shut down the car and restarted it.
I have cleared it again.

My question is how urgent is the issue?
Can I ignore it until I’m back home?

And does it change your answer if I’m in Texas now at 234ft of elevation but am heading to Telluride at 9000ft?

 

[MCtree]

Also… when I clear the code I notice that the scanner still says I have code P0441 as a “permanent” code even though to check engine light is off now.

 

[linuxgod]

I think permanent codes require a few cycles without issues to clear

 

[MCtree]

I think permanent codes require a few cycles without issues to clear

Thanks. I’ll watch for it.