EVAP Error Codes and Random Unknown Part

Hello 4Runner gang. This is my first post here.

My wife's 2022 4Runner threw a solid check engine light this morning. My reader showed 6 error codes relating to the EVAP system. When I cleared the codes, the check engine light went off and has stayed off. However, it's still throwing PO455 and PO441 codes. Any advice on these codes will be most appreciated.

The second issue is I found this random part lying loose in her engine compartment. I assume it was left there from her last oil change. It has "Low" and "Normal" level markings like a dipstick, but I don't see any place that it could possibly go. Can any of you ID this thing for me?



Thanks so much in advance.

Matt

 

The yellow stick is the washer fluid level check.

PO455 and 441 are probably from a loose gas cap.

 

If I recall from my 4th gen days, a bad gas cap (or not screwed on tight) can throw several evap codes. Worth a check, particularly since your truck is so new. I believe the yellow thing goes in the washer reservoir.

 

Thanks of the quick responses, folks.

The gas cap was the first thing I checked. It appears fine, visually, and there's a noticeable "click" when it's tight, which I believe is correct.

So, does the washer fluid dipstick just slide loosely into the reservoir and hangs out there?

Thanks, again.

Matt

 

The auto parts store should be able to test it.

Yeah it just sits on the shoulder that's at the top.

 

They prob over-filled it with oil. Happens a lot might want to check that out?

 

How is that going to throw evap codes?

 

Thank you! Random part mystery solved.

My 2023 Tundra uses the same gas cap as my wife's 4Runner. I'm going to swap the caps and see if the error codes go away. Otherwise, we have an appointment at Toyota Service tomorrow afternoon to get it checked out.

I'll update this thread when we get the EVAP problem sorted out.

Matt

 

Oil level is right in-between the "Low" and "Full" marks on the dipstick, but thanks for the suggestion.

Matt

 

I swapped gas caps, cleared codes, and it's still throwing the same 2 EVAP codes, so I guess I can rule out the simple gas cap fix, unfortunately.

On the bright side, this is the first problem we've ever had in almost 2 years and 25K miles (it's a 2022 that we bought it in the fall of 2021). Hopefully this isn't an omen of things to come.

Matt

 

Not totally sure, but some codes might remain readable after the CEL is out until a certain amount of cycles and conditions are met. So it’s still possible it was a gas cap not being cinched down all the way. Maybe drive it for a while before taking it to the butchers…I mean dealer.

 

Good to know. The dealership is an hour away, so that should give it time to cycle and/or meet any necessary conditions. We'll probably get there and it won't be throwing any more codes.

It's times like these that I relish the simplicity of my fully restored 1981 CJ7. I'd dive into any problem on that thing without a second thought. Not so much on these new space ships.

Mat

 

I had the same exact code plus a few more EVAP related codes on my truck for the last month or so. Replaced the gas cap but didn't help.
I finally changed the charcoal canister, purge valve and the vacuum hose yesterday. So far so good.
The dealership will do a smoke test among other things to see where the leak is happening. Hopefully it's not an expensive endeavor.

 

Thanks. With only 25K on the odometer, I'm assuming any fix will be covered by the warranty. I wouldn't even know where to find the canister, purge valve, and hose, nor do I really care to. It's Toyota's problem, for now.

Matt

 

Unfortunately time for the smoke test.

 

"...time for the smoke test."

NEVER say that to an electrician...

 

25k is quite early for any of those things to throw an error code. It is Toyotas problem for now.
Do you regularly 'top of' the tank at the bunk when filling?

 

Well, it's my wife's ride, so I'm not sure what her tank filling habits are, but I will ask.

She said she fills until the nozzle clicks off and that's all, so I don't think over-filling is the problem, but thanks for your question.

Matt

 

I don’t go by those marks. You sure it’s not a full mark then an overfull mark?

 

Oil level is fine. Besides, as mentioned, oil level shouldn't have anything to do with the EVAP system. But thanks, anyways.

Matt

 

Update: The service tech took a brief look at my wife's 4Runner, saw that the check engine light was no longer on, and told her it was nothing to worry about and sent her home with no further diagnostics. He also reiterated what McSpazatron said above about some codes taking a few driving cycles to clear.

So, basically there's no definitive answer to what caused the check engine light to come on, or why it went off after clearing the codes, or why it was still showing 2 EVAP codes after clearing them.

For sure, I will hook my reader back up and confirm whether or not it's still throwing the 2 codes when she gets home, since the service tech couldn't be bothered to do the same 30 second check, while my wife was there. Did I mention I hate dealerships?

Matt

 

I'm still waiting to hear about the overfilled oil and the "overfill line" on the dipstick explanation.

 

Some of those codes don’t clear internally after one or two drive cycles. It might take a bunch, depending on if all the conditions it needs to see occur during the drive cycle, and how many times it needs to see the same condition.

Personally, I wouldn’t worry about it. The fact the light is out is probably telling you the problem isn’t currently occurring. But the computer is still monitoring to make sure the problem is gone for good. Probably it was just a gas cap that didn’t get cinched down all the way, or didn’t get a good seal due do junk on the rubber or something.

 

Something to consider - when refueling, when the gas pump clicks off, do not keep trying to get more fuel in the tank. It will cause problems in the evap system when liquid fuel gets into the canister.

 

Already asked and answered above. She fills until the pump clicks off, no more.

Update #2: The 4Runner is still showing the PO441 EVAP Incorrect Purge Flow error code. I'm happy to see the PO455 Gross Leak code has gone away. Hopefully the remaining error code just needs a few more driving cycles to clear.

I did find out that my wife wasn't aware that you are suppose to tighten the gas cap until it clicks. I assumed everyone knew that. She said it was raining the last time she filled up, and she was in a hurry, so it's very likely she didn't get the cap on tight enough.

Thanks for all the comments and support, folks. This seems to be a very helpful forum.

Matt