Emissions - Gas Cap Pressure Test

[blisted]

In attempt to register my vehicle in DC here I recently failed the Gas Cap Pressure Test.

I know my fuel filler neck has a crack in it, but I wanted to see if anyone knows what the test consists of exactly. As in does it test the gas cap by itself? Or the cap and filler tube? (not sure how that would be done immediately.. but wth)

I have an aftermarket tube on the way but in the end im trying to deduce if I need a new cap also.

Thanks!

 

[97ranger xlt]

not sure in dc but in ct they just pressure tested the cap itself.
you could get a new cap but it is strange that the cap may fail but the truck doesn't throw a code....

 

[UrbanRedneckKid]

The cap and evaporative emissions systems are tested separate.

If your cap failed, get a new one.
And apparently your filler neck wasn't leaking when they tested it.

At least you failed for something cheap