P04F0 code after full tank fill up

[Cabby30]

Hi all,

My trucks thrown a P04F0 code.

The first time this happened was after filling up completely, then immediately going home and parking in my driveway, which is downhill. It then sat for two days. When I went to work, the truck stalled twice as I made my way to the freeway. Once I got to the freeway it stuttered a few times but then after about 15 miles truck was back to normal. The code did not actually indicate for this first instance but the driving characteristics were similar to today.

The next time was today. I filled my truck tank on the way home, truck sat overnight, downhill in my driveway and then I drove it in the evening. I noticed a few stutters while driving but it didn’t stall. Truck then threw a P04F0 code merging on the freeway. Other than it disabling the active cruise control, truck drove great for the next 3.5 hrs / 200 miles.

Googling the code:
”The P04F0 code on a Toyota indicates an "EVAP System High Pressure/Load Purge Line A Performance" issue, meaning the vehicle detects excessive pressure or restricted airflow within the emissions system, often caused by a faulty purge valve, stuck check valve, or clogged canister. It typically causes a check engine light, rough idle, or hard starting.”

I don’t top off the truck. Once it clicks, I stop fueling. Not even two clicks.
The only thing I can think of is my driveway is steep and I park facing down slope. This to me is weird but the only thing that I can think of as a potential hypothesis.

Truck is a 2024 with 28k miles.

Lastly, the code cleared after unplugging battery for 15+ mins.

Any ideas?

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[Andrace]

Could be the driveway, but could also be a parts failure. See attached

MONITOR DESCRIPTION When pressure pulsation caused by purge VSV operation in the boost range is less than the threshold value, it is determined that a high load purge line malfunction has occurred and a DTC is stored.

 

[Cabby30]

Could be the driveway, but could also be a parts failure. See attached

MONITOR DESCRIPTION When pressure pulsation caused by purge VSV operation in the boost range is less than the threshold value, it is determined that a high load purge line malfunction has occurred and a DTC is stored.

Thanks for sharing this! I’ll keep monitoring the situation.
I find it hard to believe Toyota would mess up a full tank on a (steep) driveway with the amount of experience they have, but who knows. That’s the only thing that is common with the two incidents.

 

[Reconsnake]

With the truck still under factory 3 year/36k warranty, why not take it in if you see that malfunction again?

 

[Cabby30]

With the truck still under factory 3 year/36k warranty, why not take it in if you see that malfunction again?

I definitely will but I had just departed on a road trip and after checking all the fluid levels, oil pressure, engine/trans temps, etc. I chose to proceed. It drove great/normal even with CEL.

 

[EatMyTaco]

When your back home, maybe park it the opposite direction in the driveway?

 

[bajathree]

 

[Sagebrush]

this happened was after filling up completely

After the spout clicked off, did you add more fuel?

 

[Cabby30]

After the spout clicked off, did you add more fuel?

Nope. Never do. Once it clicks, I hang up the hose

 

[chasea1989]

I've worked on plenty of toyotas with evap issues in my shop, but this is definitely a new one. My educated guess would align with someone above about it being the steep angle of the driveway (which would definitely be a design oversight), but I'll agree about trying to park it the other direction to see what happens. fuel could be creeping back up a vent line and into the canister, especially when the tank is full.

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