Gas Cap

[mrfitter]

My son used his Car MD on my 2003 Explorer Sport Trac and it came back with a code stating that I need a new gas cap, But I noticed the little metal flap where you insert the gas nozzle is stuck in the open position. Can that be the cause of the gas cap failure ? Anyones input is appreciated. Thank You

 

[RNGRDVE]

The metal flap will not cause the lt, some vehicles are actually produced without that flap. The fuel cap is the most common cause of the lt for the evap system. If the cap doesn't repair this you will need to take it to a shop that can perform an evap system pressure test to find the leak. Your not hurting anything with this code it just means you're killing the ozone layer and the Govt' says you're a bad boy.

 

[Joe Dirt]

The filler neck may be cracked... Look very closely at the neck where the cap sits in and on. Very common problem. If it is, a1auto.com sells a nice replacement.

 

[swshawaii]

From your owners manual:

If the “Check Fuel Cap” indicator illuminates and stays on after you start the engine, the cap may not be properly installed

The fuel cap gasket may not be seated properly, lubricate lightly.
Also possible a vent hose is clogged or dislodged from the connector.
Warning indicator should turn off after a few cycles, if it's corrected.

 

[gtyates]

On my '05 I also noticed that the little flap was stuck open. Using a small flathead screwdriver I was able to unjam the little internal spring and since then it has worked well. And yes this can cause the light to trip due to the pressure in the fuel system not being correct. I also sprayed a small amount of Wd40 on the spring. It has been about 6 months since then and the flap now stays closed as it should and no more CEL for me. And yes I tried replacing the gas cap first and it did not keep the CEL light off after I woudl reset it by pulling the negative battery cable. Only getting the flap to close seemed to resolve it.

 

[RNGRDVE]

And yes this can cause the light to trip due to the pressure in the fuel system not being correct.

The flap is not sealed and will not cause a light to come on. If you look above the cap there is a open area to help vent the neck while fueling. If the flap sealed it off then the area aboce would have to be closed off to create a seal. The most common cause of that code is a fuel cap but could be a # of other things causing the the fuel system to not hold vapor pressure.

 

[mrfitter]

Thanks for the input everyone.

 

[MidnightRebel07]

I move the rubber O-ring up towards the end of the shaft of the cap and clean all the dirt off of it everytime I fill up. Some members on multiple sites say they put a small amount of vaseline on the O-ring to make a good seal.

 

[Joe Dirt]

...aaaaaand we have a new sig line. Thanks! JDraper is now off the hook...

 

[MidnightRebel07]

I can do better, I figure someone was gonna use that. That's why I worded it like that, LOL.