Small Evap leak

[Baseshakers]

My pig ('05 LJ) is throwing code P0456, a small EVAP leak. The gas cap is stock, and the o-ring looks fine and clear of debris. Any other suggestions? If I try the smoke machine test, should I simply plumb it into the filler neck?

FYI I reset the code, drove ~50 miles... and it wasn't enough to pass inspection. Didn't throw the code again until almost 100 miles total!

[ASauer17]

Spend the $20 and replace the cap to see. One of my caps some how rotted inside.

[Kurt]

Can you check the IM status with your reader?
If so you may be able to clear the code and drive it just long enough for the IM to go "READY" and then quick get it inspected.
The evap system usually needs you to get the Pig up to temperature, have most of a tank of fuel and drive at highway speed for a bit for it to do the evap test and then it'll set the IM status to Ready. Of course the MIL light may come on if it senses a leak again.

[Baseshakers]

I have the OEM locking cap, so I'd rather not give it up... But obviously I need to fix the problem. The forums claim that the crapyzone caps don't seal well, but I'd rather not go back to the dealer. Any brand suggestions?

I am able to read the readiness, and I had two "not readys" which prevented my pig from passing inspection. I checked every time I stopped, and it never went to "ready".... Until the light came back.

The code has come back at least twice now (I tightened the cap and reset it previously) so something "permanent" is going on.

[del_TJ]

I've used a Stant one for years without problem.

Stant 10591 Locking Fuel Cap
http://www.amazon.com/gp/product/B000B8 ... detailpage

[BlackNBlue-ISH]

I once realized a hose had become disconnected. Reconnected it and code went away. Maybe it's something simple like that

[beaker]

I'll put a dollar on the gas cap.

[ASauer17]

I went thru 3 locking caps.. They are just as cheaply made- sadly

[Carl McFly]

Another vote for the gas cap. Mine still throws that code once in a while. One option is to remove and reconnect the hoses at all the EVAP system components - evap canister, purge solenoid, all of it. Stress the hoses and look for a small split on the hose where it connects

Or just replace the gas cap

[Baseshakers]

So it wasn't the gas cap... I bought a new one, drove 100+ miles and the code is back. What should I check next?

[beaker]

New OEM or new aftermarket?

[Baseshakers]

New aftermarket (Stant)

[beaker]

Hmm

Try this!

http://www.thesamba.com/vw/forum/viewto ... ?p=5282178

[Baseshakers]

I actually have an old fog machine... Maybe I should modify the old gas cap as my "input" for the smoke

[Frank]

I have a screw in keyed cap you can have if you want to try that. FjR68