What's up Scion lovers.

Long story short I was getting evap codes P0441 P0455 P0456 so I tested purge solenoid, it's good. Next step was to do a smoke test, then test the canister. Smoke test failed with smoke coming out of the gas cap.

I used the original OEM cap and the one I bought off amazon, 5 stars for my scion. Same amount of smoke with both caps. I also tried some electrical tape to try and make a tighter seal, same result with smoke.

Car was in a drivers side rear accident 5 years ago before I owned it.

I'm thinking maybe I just need to replace my whole fuel filler neck because the one I have just cannot make a tight seal with the gas caps.

Just seeing if maybe anyone has any advice before I go ahead and spend $150 on the filler neck.

Here are images of the caps and opening of the filler neck.

https://imgur.com/a/dedQr2s

thanks so much for any help!

 

How difficult is the filler neck swap? I'd probably try another cap before dropping $150 for the filler neck.

Are you by chance topping off fuel at the brim? That's the only time my tC popped all three codes. Now I just fill it until the pump shuts off, plus one goose. Keeps liquid fuel out of the canister.

 

If smoke is coming out then the rubber seal is not contacting the filler neck??
Whats that dent in the outer ring from? Is that stopping the cap from sealing?

 

Yes I used to top it off to the nearest dollar, I remember one time maybe 2 months before the codes popped I def put too much in the tank.

yea that makes sense that the rubber O ring is not making good contact, I just don't know how to fix it or what to do

 

That could be the source of your incorrect purge code. If memory serves, the only things that throws P0441 is a bad purge valve (and or related power/ground connections) or a clogged canister. If it's the canister, it might explain the new cap (or even the old one) failing the smoke test. At least that's what happened to me.

Ultimately I got lucky and didn't have to replace anything beyond the potentially unnecessary fuel cap. Following the auto-shutoff plus 1 goose apparently allowed the liquid fuel to evaporate. After two to three tanks of fuel, it stopped throwing evap codes.

 

so you're saying a bad canister is why there is fumes escaping from my gas cap?

 

It's possible. If the canister is clogged, there's nowhere else for the smoke (or fuel vapor) to go but out the filler cap. Your cap has an o-ring seal but it also has a hole in it to allow the evap system to vacuum fuel vapor from the evap tube (that parallels your fuel tube at the filler neck.) Sorry it's just a guess. The way my situation worked out, I never actually found the culprit and simply assumed the clogged canister unclogged itself.

 

Thanks so much for your help I was wrong about how it worked then I thought if the car is off the canister valve would be closed.

I think I should figure out a way to plug that filler hole 100% and clear the codes and see if the codes come back.

I did purchase another cap also but I just don't know how that will work we'll see.

Just have to figure out a good way.

Then of course if the codes come back, move to the only thing I didn't check, the canister as you said.

ty ty ty