P0442, check gas cap, can’t figure it out

mm3846

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I’m still stuck on this.

Got the fuel pump recall done, that fixed the “can’t fully fuel up” issue that a lot of people have. I’m able to get 18-19 gallons in before the pump shuts off where I used to only get 16-17. The stalling/misfire I was getting after fueling up is gone too.

DMTL pump and purge valve replaced last summer, doesn’t mean they aren’t bad again. Smoke tested the truck, it ran out through the vent behind the filler neck. No other leaks on the fuel or engine side. New gas cap didn’t help.

I searched around, the answers seem a little all over the place. One guys says a new purge valve fixed it, another said charcoal canister. What’s wracking my brain is the code is for a LEAK. There is no leak. Any ideas?
 

Rover Range

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Make sure the fuel cap is sealing against the filler pipe.

The filler pipe can recede into the rubber housing, causing the cap not to seal against the filler pipe.
The rubber housing is basically pushing the fuel cap away from the filler pipe.
 

mm3846

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Make sure the fuel cap is sealing against the filler pipe.

The filler pipe can recede into the rubber housing, causing the cap not to seal against the filler pipe.
The rubber housing is basically pushing the fuel cap away from the filler pipe.

I saw this in another thread, but mine is sticking out enough that the cap seals. I’d imagine the filler neck has to really turtle itself in there to not seal against the metal filler.
 

Rover Range

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I saw this in another thread, but mine is sticking out enough that the cap seals. I’d imagine the filler neck has to really turtle itself in there to not seal against the metal filler.
People that shove the fuel filler nozzle into the filler neck, can push it in.

Check the evap system purge valve solenoid. It's on the the top, left side of the engine valve cover. Remove it and blow through it, should be sealed.
 

jlglr4

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Smoke tested the truck, it ran out through the vent behind the filler neck.
You say there is no leak, but this sounds like a leak. The vent on the tank connects to the charcoal canister, so smoke coming out near the filler is not normal. Was this leak fixed and you are still getting a code?
 

mm3846

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You say there is no leak, but this sounds like a leak. The vent on the tank connects to the charcoal canister, so smoke coming out near the filler is not normal. Was this leak fixed and you are still getting a code?
Smoke was coming out the vent, which is next to the filler. That’s normal when pushing smoke back into the fuel tank.
 

jlglr4

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I guess that would be the canister vent, but shouldn’t the canister vent solenoid be closed during a smoke test of the EVAP system? I assume you’d want the system closed and slightly pressurized to look for leaks.
 

mm3846

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I guess that would be the canister vent, but shouldn’t the canister vent solenoid be closed during a smoke test of the EVAP system? I assume you’d want the system closed and slightly pressurized to look for leaks.
It is open by default from what I understand. I don’t have any control over it with the GAP tool.
 

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