gas tank has alot of pressure

[rockyroad217]

ok so yes my check engine light is on..its code P0446..it comes on all the time lol..i figure it has something to do with why my gastank has so much pressure in it..if i unscrew the gascap, it vents wayyy more than it should be..not so bad that it will blow the cap out of my hand, but i can definitely feel the pressure..i figure its the evap purge solenoid valve, but no one can ever find it..does anyone have a parts number? i'd hate for gm to order it, and it be the wrong part after i already paid for it lol

[mechanicix]

If its any help the evap canister is under the bed next to the gas tank. However your supposed to have pressure in the tank, if there is no pressure it will throw the same code. had to replace the tank on mine it was rusted through.

[rockyroad217]

yea, i know where the evap is..and i knew it was supposed to have a slight bit of pressure, but this isnt right at all lol..i can smell gas fumes leakin from around the gas cap it gets so bad at times

[AVTekk]

wrong, there is supposed to be vacuum, not pressure.

if there is indeed ANY pressure in the tank, then you need a new gascap, youre is vented to keep pressure from building up.

if its excess vacuum that you have (it will sound and feel very similar when you remove the cap) then youll need to fix the purge solenoid.

[s10bbagged]

yeah i would say that you need a new gas cap to. thats what goes on most cars or trucks all the time. it will build pressure in tank if its not venting right

[rockyroad217]

hmm maybe it is vacuum..all i know is, the gascap is about 2 months old and was the first thing i replaced lol

and dave would i be wrong to say pressure? isnt there pressure in a vacuum? lol

[jeffery_843]

my truck does it too. whenever i take the cap loose it feels like pressure because it does push up on the cap. seems like it does it more if the fuel is getting close to empty. can this cause a problem? wondering because i just say fock it, and loosen the cap carefully everytime

[rockyroad217]

im sure mines the solenoid valve, because it doesnt do it when the check engine light isnt on, but as soon as it pops on is when it starts doin it lol..i was just wondering if anyone knew the part number because i dont wanna pay for a part and the dealership order the wrong thing