Evap questions - Toyota Nation Forum : Toyota Car and Truck Forums

BeigeCorolla · 12-12-2011, 02:04 AM

Hey guys,

havent been on for a long, long time. So EVAP codes thrown, money spent codes still there would be the short version of this epic EVAP saga.

P0446 came up while going home one night.
Cleared the code twice i believe, after the second reset, P0446 + 441 came up.
Checked the forums and also google, VSV was a thing. Tested the VSV, no audible click, thus got a new oem. Reset the code, couple days of driving, drive cycle completed BAM CEL comes up. Checked it on the reader and this time only P0441 comes up. So did my hw again, found that the next probable cause is the Valve in the front. Checked with a power source, and it works fine. So did a smoke test, and my mechanic found some hose leaking, due to it not be tight enough of sorts (cant really describe the connections) but tightened, code cleared. ANd couple days later CEL P0441 comes through. So at this point I asked my mechanic what else could be an issue, and thinks its the pressure sensor near the VSV which probably has called it a day. I was wondering wouldnt the pressure sensor throw its own unique code? And also wouldnt it be safe to assume that its either a clogged line or fouled canister?

chuckoff · 12-13-2011, 03:37 PM

Probably canister failing. Canister usually comes with VSV and vapor pressure sensor attached.

BeigeCorolla · 12-25-2011, 04:00 PM

Hey Chuckoff,

Thanks for the reply!. I thought that too, then suddenly a couple days ago, the light extinguished itself. Weird, probably colder less humid weather had some effect, dont know. But yea its off and im just gonna go with it.

TurboRolla1 · 01-10-2012, 03:36 PM

Is the light still off?

JFM-jr · 01-12-2012, 09:57 PM

I get a 441 code in my Prizm whenever I fill the gas tank. If I go limit the refill to only 3/4 of a tank it does not come on.

fishexpo101 · 01-13-2012, 09:13 AM

Do you top the tank off on a regular basis or just pump until it automatically shuts off?
If you only do partial fillups, has the light ever come on?
Do you sometimes get a strong gasoline odor toward the rear of the car, sometimes most noticeable after driving soon after filling up the tank?

If you don't overfill the gas tank, partial fillups never make the CEL come on, and you occasionally get a fuel odor after exiting the vehicle after driven some distance right after a fill up. There is a good chance that you have a bad cutoff valve or cracked EVAP/vent hose at the top of the tank. Those tended to crack very easily and show all signs of a bad vapor canister. If you want to get it fixed right, I'd suggest you get the EVAP system "smoke" checked. They generally will pressurize the system and/or fill with a tracer gas - then use a sniffer wand to go over every inch of the EVAP system. Will pinpoint exactly where the leak is.

I've been through a similar situation with my 2002 Corolla - everyone told me it was the purge valve, VSV valve, and bad vapor canister - minimum cost would be around $400 + labor. Until I finally found a shop that was willing to do the EVAP smoke check - took then less than two hours to pinpoint the leak - bad cut-off valve at the top of the tank. Tech mentioned that it was only a $30 part, but the labor was pretty steep, as the tank has to be dropped. When I suggested that I just buy the cut-off and do it myself, the tech even printed out the location and a service guide to help me fix it - and this was at a Toyota dealership.

JFM-jr · 01-14-2012, 07:40 AM

Thanks for the info. I purchased this car last year and after getting the CEL i looked around the evap system and took note of a few things the prior owner did (he never told me about the CEL and it came on after the first time I filled the tank). The charcoal canister under the car and fuel cap were new. So the prior owner had begun to try and have this issue chased down things got expensive and he still had the CEL so he dumped it. I am fine with it I got this car car for a song and dance and is the best money I have spent in a long while. It took me about a month to put the pieces together and figure out the CEL came on ONLY after a fill up (i dont top off). If I run the tank down the CEL extinguishes. Here in NY they will not pass the car with a CEL (for any code) so I may play the game and inspect it and forget it. I've gone about a month now with partial fillups (i put 30 bucks and gives me 3/4 tank) with no CEL. Well I did get a 171 lean code but thats another thing im gonna try to remedy today(clean my MAF). This site is great thanks again.