Gas cap sets off check engine. Its driving me insane.

[evilredGS]

My gas cap keep setting off my check engine light. If I tighten the cap, the light goes away. I've pulled the codes and they support this. Are there any fixes for this other than replacing the gas cap?

 

[1gcrazy]

I've read something about this....Something to do with removing the charcoal canister... Did you remove yours?
If you did, try making just a breather/catch can... Lemme try and find the site.

Here....maybe I was a bit off....
http://dsmtuners.com/forums/showthread.php?t=224901&highlight=emissions+101

I think the gascap throws a code because it says its off....like leaking gas fumes....
I dont have my cap here to look at but check for a gasket you might be able to change or make a new one out of rubber.

 

[DSMunknown]

I think the gascap throws a code because it says its off....like leaking gas fumes....
I dont have my cap here to look at but check for a gasket you might be able to change or make a new one out of rubber.

I agree. Just replace your gas cap with an OEM cap and call it a day.

 

[FORMONTOYA]

Current fuel systems are "mandated" to be a closed system. With that in mind the gas cap needs to function properly (ie.....close).

Just purchase a new gas cap, they're cheap.......really.

 

[EclipseTrbo420A]

Heres one for you guys too. When I unscrew my gas cap I can hear the loud hiss of the pressure being realesed...WTF the cap is deffinately sealing, But my light will NOT go away and I cant pass inspection with a light on. Where else should I look? Thanks guys.

 

[Dream On]

Look into the fuel pump assembly. Did you recently put in a fuel pump and possibly damage the float?

 

[EclipseTrbo420A]

Nah the fuel pump had been in there for years now, and my floater works too. I have a AFPR and my guage reads pressure for hour or 2 after I turn the car off so I know my system is sealed. I want to get inspected legally this year but the gas cap is holding me back.