Whenever I fill up gas I'm not getting a hissing noise, so I suspect I have a leak in the fuel system. Should I replace the gas cap first and work my way down?

 

How is your gas milage? Do you have e-check where they check your gas cap for leaks?

 

Gas milage usu high 20's, in accordance with the EPA numbers for my model Neon (22/27).

Edit: Those nums were for ATX not stick (which are 29/41). So this means my MPG numbers are below EPA, which sorta sucks. :/

We have an e-check where they check gas caps, but the DMV feels my car isn't old enough for mandatory smog. Dunno if Autozone would have a gas cap device for loan.

A while back I had a EVAP canister-related CEL (mechanic suggested going to dealer for some sort of "smoke test"), for some reason it went away and the ON-OFF-ON-OFF-ON only brings up 55, it's possible it could be a fuel leak returning to bite me in the rear.

 

It's possible you have a gas leak, but do you notice any odors?

 

Nope. On the rare occasions I smell something it's inevitably coming from idling behind a giant truck. But I don't "smell gas" every time I drive the thing.

 

Well is it neccessary to hiss? I dont know how it should be on a neon, but on my honda it didnt make a difference how it was set up. It was carbed so I could play around with it more, but if I removed the float vent to the gas tank I got less pressure when taking the cap off, and when it was on, it hissed alot. Seemed like more than it should. Didnt affect my mileage. My neon doesnt hiss

 

Thought it was.

 

hmm, well maybe I have a problem too. Ill watch this thread see what comes of it

 

What're you getting in terms of MPG? I get like 29 with highway driving...and I'm a stick; I should be getting somewhat better numbers. :/

 

I pretty sure I have gas leak then...
I get about 15mpg
my cars reaks of gas most the time
and no hissing sound.

How do i go about fixing it ?