Check Engine Light - EVAP error codes

My Check Engine Light is on, along with the TRAC OFF / VSC TRAC lights.

Last time I did a reading I just got the P0441 — EVAP Emission Control System Purge Flow Fault.

I just did a new reading and got all of these:
P0171 — System Too Lean
P0440 — EVAP Emission Control System Malfunction
P0441 — EVAP Emission Control System Purge Flow Fault
P0446 — EVAP Emission Control System Vent Circuit Malf
P0171 — System Too Lean
P0441 — EVAP Emission Control System Malfunction
P0441 — EVAP Emission Control System Purge Flow Fault
P0446 — EVAP Emission Control System Vent Circuit Malf

On the last 4, there is a “PENDING” icon. What does that mean? I used an actron OBD II AutoScanner and the ignition was on but not the engine.

I’ve done a battery reset a few times, the warning lights disappear but come back eventually.

The gas cap is on tight, but I’ve read that if the seals are bad it might need replacement.

I’m trying to get the car ready for a smog check. I’m guessing it will automatically fail because of the check engine light, but will they give me more information about what needs to be done?

Where should I start with this?

Thanks!

 

Pending means the system it relates to isn't behaving normally, but not enough to cause a light. A problem with the evap system can cause a lean condition, so figure out the problem with the evap system first and it might solve your P0171 error. You wont pass with a CEL.

First buy a new OEM gas cap, sometimes that fixes it

 

I wound up dropping my tank and replacing ALL the seals in it as well as the charcoal cannister. Used only TOYOTA parts from an online TOYOTA dealer. Replaced the fuel pump with a DENSO while I was doing it.

Evap codes have been gone for a few years now. Those gaskets and valves are all plastic and just are going to die after 20 years. I recommend a full replacement.

Here is my thread on what I did: The only thing not replaced in regards to the evap system was the actuator that is under the hood.

 

https://imgur.com/vylXhSw
https://imgur.com/ETnf6rW
Is there any way to say if this gas cap is good or if it needs replacement?

 

The only method is a visual inspection but I don't think that would catch everything. If you have another 4runner you can swap them.

Buying a replacement cap is just one of those things you do and if it works good and if it doesn't at least you'll know that you aren't getting pawned by an issue as trivial as a gas cap.

 

Don't have another 4Runner...
Is this the OEM part number? (77300-53010)
Is there really no way of knowing other than spending $30 just to make sure...? Seems silly to do if there's nothing wrong with the old one, and so far I haven't found any answers on what to look for...

 

I don't think there is any other way. You can use the gas cap off a Camry of the time I think. Sure it sucks to buy a part you might not need, but there's a chance it could save you a lot of time and money, and it's not that hard to do or expensive to check. Anyway the gas cap is 22 years old, not like it's brand new.

You can ask people on other forums they'll probably recommend something similar, and you don't have to follow my advice.

Yes that part number is correct. I can find them for 22$ online. If you searched by a different vehicle that shares the same cap I'm sure you can find it for a bit lower, but that's something I'll leave to you if you want.

 

Not directly related but double check all the areas around the intake. If there is a vacuum hose or something pulling air in, this could trigger all of this stuff. I know the codes are pointing in a different direction but all this stuff is so integrated than any other leak can trigger a code.

 

I could see the System Too Lean. But I would be surprised that EVAP codes would come from the intake.

 

Took it to Toyota for a diagnosis - they wanted $595 just to diagnose! I asked if that would cover any repairs and they said no, that's just diagnosis. Lmao.
Found a small, local shop instead and he only found the system too lean error code. He found a loose air intake hose and helped me tighten it and deleted the code, charged me nothing. Never going to Toyota again!
I have driven for 120+ miles and the CEL never came back on.
Took it to smog today, but they said they can't do it because they see two EVAP error codes:

• P0441: EVAP system incorrect purge flow
• P0446: EVAP system vent control circuit

I ordered the OEM gas cap from Amazon (Toyota wanted $45 for it, lol) so hopefully that'll take care of it.
Do I need to delete the error codes after replacing the gas cap and then drive for ~60 miles again? The CEL is still off.

 

glad you found it. I guessed it right this time with the air leak.

 

Glad it's resolved. I'd delete the codes, if they come back the car will let you know

 

He found the lean issue. He still has the EVAP codes he needs to fix.

 

I agree with you the diagnostic price was outrageous.

Beware "OEM" parts on Amazon. You may have gotten a fake. Although...how bad could they fake a gas cap and get it wrong?

 

I don't know about the Phoenix/Scottsdale area, but I lived in Yuma for nearly 30 years, and never got a single vehicle smog tested. The air in Yuma is so cruddy to begin with, they don't bother with smog tests on cars. That includes trucks, of course. Like my Hilux pickup, the Chevy Luv I used to own, etc.

Just making note that not ALL of Arizona get the vehicles smog tested. I live in S. Oregon now, and still no smog tests. I just get lucky that way, I guess.

I would guess that yes, you'll need to clear those codes. If the problem is, in fact, repaired, clearing the codes is certainly easy enough. Just pull the negative terminal off the battery for a minute or two, and they are cleared.
To ensure the problem IS actually cleared, take 2 separate 10 mile runs. Toyota computers are set for "two trip logic", meaning the code has to show up on two separate trips you take before it will set the code. IE: start the truck, drive it for about 10 miles, under different conditions, faster, slower, in 4 WD, in 2 WD, and so on. Then park it and shut it off for about 10 minutes or so, the start it again, and do it all over again.
If no codes show on the second trip, you can be fairly sure the problem is dealt with. Best thing to do is get a cheap code reader at any auto parts store. One that will read OBD II coding. Plug it into your OBD II reader jack in the cabin, and you can keep an eye on what's happening in the vehicle. You can get a decent code reader for about $20 to $30. You can even leave it plugged in while driving, and have your passenger watch what's going on. You could yourself, but it's a better idea to keep you eyes on the road, not your code reader! You can always check it when you're parked someplace.
A much less expensive way to check on the CEL light than taking it someplace to have someone else check it. Most shops have very expensive code readers, which give much more information, but they have to pay for them somehow You're wallet is where they get the money for them...

Good luck!
Pat☺