[jjock]

i just bought a locking gas cap for my 1997 TJ and i dont know if i should use a vented or unvented cap?!?

 

[amerijeep]

I have to admit, I don't know myself. I just replying to give this a 'bump'.

 

[1BLKJP]

I believe our Wranglers use a sealed gas cap. Pretty sure that's the reason why they do the seal test on it here in AZ, to make sure they are sealed properly and not leaking..

 

[AzTJ]

You'll want a regular one, non-vented. Ever leave your gas cap on loosly and see the check engine light come on? Thats telling you that there is a "EVAP Emissions Leak"... because our gas tanks need to keep pressure to run properly because the pump is inside the tank(thanks Jeep!).

 

[Scooby]

I had the light come on awhile ago, and I purchased a new locking cap. I just asked for a locking cap to fit my 2002 Sport. I have had the light come on since the new cap, so can you visually tell if you have a vented or non vented cap? I just want to double check the parts guy. Thanks, Scooby

 

[jjock]

You'll want a regular one, non-vented. Ever leave your gas cap on loosly and see the check engine light come on? Thats telling you that there is a "EVAP Emissions Leak"... because our gas tanks need to keep pressure to run properly because the pump is inside the tank(thanks Jeep!).

how do you know that?

 

[binaryking]

I had the light come on awhile ago, and I purchased a new locking cap. I just asked for a locking cap to fit my 2002 Sport. I have had the light come on since the new cap, so can you visually tell if you have a vented or non vented cap? I just want to double check the parts guy. Thanks, Scooby

Did you clear the codes? Sometimes those codes need to be cleared before they go away.

 

[AzTJ]

how do you know that?

Worked at an auto parts store for over 2 years, you learn stuff - It happened on a daily basis almost, people(mainly girls) would come in and get thier engine light check for free and it would say that... and not just Jeeps, just about every vehicle will have the check engine light come on if you forget to put the cap on properly.

 

[Texapple]

Worked at an auto parts store for over 2 years, you learn stuff - It happened on a daily basis almost, people(mainly girls) would come in and get thier engine light check for free and it would say that... and not just Jeeps, just about every vehicle will have the check engine light come on if you forget to put the cap on properly.

ummm........wonder how many girls have asked that very question on this forum.

 

[jjock]

Worked at an auto parts store for over 2 years, you learn stuff - It happened on a daily basis almost, people(mainly girls) would come in and get thier engine light check for free and it would say that... and not just Jeeps, just about every vehicle will have the check engine light come on if you forget to put the cap on properly.

well that doesnt work because my check engine light is always on. i dont need anyone to tell me to fix it. i already did and the mechanic couldnt figure that shit out. it was the crankshaft sensor but he replaced the sensor and it still going off. i think its prolly the exhaust leak in my manifold. but anyways.. how else would i know vented or non-vented?!?

 

[AzTJ]

lockable caps usually arn't vented, if they are, they usually have a button to push on them.

 

[Jerry Bransford]

but anyways.. how else would i know vented or non-vented?!?

Smog laws require unvented gas caps and zero gas fume emissions that a vented cap would allow. The smog system in your Jeep tests for that and it'll illuminate your Check Engine light if the gas cap is vented or loose.

 

[NWilhelm]

Bottomless pit of Jeep knowledge

so very true.