YACT: Air comes out when I open the Gas knob

The pressure you are experiencing is from the gasoline expanding in the tank from heat, this is absolutely normal.

 

[Templeton]

Originally posted by: whiteboy81

Originally posted by: Jejunum

Originally posted by: dman
On some cars, if you don't have the gas cap on tight enough a check engine light will come on. I don't know why.

its a emissions control. lots of gas vapors escaping your tank is bad for the environment

Don't they all eventually escape anyway?

I think it's been mandated for some time that cars have some type of emision control equipment to capture these evaporative gases and keep them from being released into the environment.

 

Yea, it's called a chracoal cannister for those not in the know.