OK so 2 weeks ago I posted on here about throwing code P0440 evap.(Changed the gas cap) did not help. Well I remember reading awhile ago someone on here said if he kept his gas tank 1/2 or above it would not throw the code. So I figure lets try this and see what happens, sure enough if I don't let it get down to 1/4 tank...the code stays away. I really don't want to deal with this the rest of my life so does this give anybody any ideas to what could be causing it.

 

Check the evap canister and all hoses going to it by the tank.

 

Thats the canister under the drivers side cab correct?

 

It's usually by the tank somewhere...and while you're under there check everything. Check all hoses for any kinks/crack and that goes for the filler neck too.

 

I just posted this a day or two ago, but was too lazy to look for it. Check the entire system, you'll find a small leak somewhere...