What would cause this? Intermittent p0441 p02420

What would cause this a p0441 and p2420 code? I replaced the gas cap and the purge valve. The codes come on randomly - I can drive 500 miles and it'll come on or sometimes after 10 miles. Any ideas? I know this is tacomaworld but not getting much help on 4runners.com

It is a 2013 with 175k miles

Thanks!

 

bump

 

If it helps (it probably doesn't) I am having this exact issue with my 3rd gen Tacoma. Both of these codes. I've replaced the gas cap, and was getting ready to tackle the purge valve. Bummer that it didn't fix the issue for you. Let me know if you get to the bottom of this..

 

You as well!

 

I've since replaced the purge valve and the charcoal canister, and I'm still getting codes.. sort of given up for now on it. The truck runs fine. The only think I can think of is maybe I have a split in a vacuum line somewhere betweentm the charcoal canister and the valve at the engine..

 

Stupid question but did you replace the gas cap with an OEM or an Autozone special? I had this issue and a cheap gas cap from the parts store didn't do the trick, but getting one from the dealership did.

 

Dang, yeah I am thinking it is something with a line somewhere since everything else hasn't worked. Truck runs fine so haven't been too worried, just annoying

I did OEM, I was hoping that was the issue since when I bought the truck it had an autozone special on it

 

Darn, worth a shot. Hope you get it sorted.

 

Before replacing any more parts, have a evap leak test done. That'll tell you if you have a leak of some sort or not. Based on the info, I am not sure a leak is your issue.

 

You need to test the vent and the purge valves for function. A techstream is needed.

Do you offroad properly? It could be dust clogging the vent valve and the system can't seal. I have to clean my vent valve from time to time on my xterra because of all the dirt roads I drive on.

 

Cool, I'll see about getting one to rule that out. What makes you think it might not be a leak? Just because it is so random?

I'll look into a techstream - does that tell you if those items are working correctly?

I bought the truck with 175k miles so who knows what the person before me did! The code came on within 10 miles of first buying it.

 

Just the code description. I'm not sure if you've tried google or not, but I believe if there's a leak, usually there's a code about an EVAP system leak. Maybe not though, which is why I suggested a test before blindly throwing more parts at it (been there lol)

 

Bumping this thread - I am still getting these codes. Wondering if anyone was able to find a resolution for theirs? I think my next course of action is to get the EVAP system smoke tested.. Kind of dreading that but it's not something I am able to do myself.

 

Actually, you can if you want to. There's LOTS of plans for smoke generators on YouTube that you can build yourself for <$50, and lots of cheap, MiC units on Amazon, FleaBay for short money as well. With respect to your codes, have you checked your vent solenoid (the other half of the equation)? It's unlikely, but if it's doing something funky, it could be having an upstream effect on the purge vv. The other think I would do is buy/borrow a scan tool with live data viewing capability, and record/watch all emission system PIDs. I expect that you will find clues here.

 

I'm not an expert by any stretch, but I don't think this is a leak in the lines. Reason: Leaks are not intermittent.

Check the wiring on the sensors. Loose connection, corroded grounds, frayed insulation, wet connections........ Or perhaps a sensor is getting wonky. (secret technical term)

175 kmiles is a fair amount of miles. Easy for wires/connections to degrade.

 

D'ohh… missed the mileage totally, for some reason I was thinking new truck. Yes, at 175K, this is a VERY likely scenario and explains all of the issues nicely. If you don't have one, buy or make an incandescent test light with at least a half-amp draw, and test ALL your grounds.

 

Same with me on my daughter's '06 4Runner (she forgot to put it back on after fueling and lost it). I ordered an "OEM" one from Amazon and it didn't fix it. Got one from the dealer and it was fine. I don't trust Amazon or eBay "OEM" any longer.

 

I am not the thread starter and I'm not sure if they will chime back in or not. A higher mileage vehicle could definitely have grounding problems. Hopefully they see this if they haven't resolved the problem already.

In my case, I am getting these two codes on a 2017 TRDOR with 60k miles. You mentioned checking the vent solenoid, I have replaced that (also called the purge valve) and I've also replaced the evap canister just in case with no change.

I did try replacing the gas cap with a new one but I did not use a factory one, I replacing it with a Stant and the problem still persists. So maybe my next course of action is to actually try a factory Toyota cap..

Really appreciate the advice here. I've been fighting this CEL for like a year now..

 

Nooooooooo… the Vent and Purge Valves (or solenoids) are two different things. The purge valve is a normally closed valve which when opened allows vapours from the system to be directed to the TB for combustion. The vent valve is a normally open vv which vents the system, and which, if it doesn't open, would in theory at least, lead to a vacuum, or partial vacuum in your system.

 

hmm okay, that makes sense. Thanks.

I cannot see anywhere in my searches that the vent valve is a singularly replaceable part. It appears to be part of the pump module which is included in the charcoal canister assembly. Is this what you are referring to?

If so, I did replace that when replacing the charcoal canister assembly.