Hi all,
Having trouble pinning down a P0456 Very Small Evap Leak(intermittent) error on my 2016 convertible with 3.0 V6 with 45k miles.
Working with my mechanic we have tried two Jaguar gas caps, a new purge valve that was reading low resistance and a new vacuum hose that the smoke test showed some leakage.
I thought I was home free with the last one but after a few days of driving the code came back.
Side note, I have noticed through trial and error that if I clear the code and fill up I will get a gas cap error within the first quarter tank. If I turn the car off and on again I can usually drive the rest of the tank out without another error whether I re tighten the gas cap or not. Then with the next fill up it will throw the amber engine light within the next quarter tank. I drive about 40 miles each way to work with mostly highway speeds so I should be tripping the evap check regularly.
Just putting it out there to see if anyone has had a similar problem.
Thanks for any response!

 

Did you get the correct gas cap for your car? I had issue with my 2015 and initially ordered the incorrect one myself and ended up going to the dealer and giving them my VIN to make sure I got the correct one.

 

I recall a recall (not even an intended pun) that was done in the first year or so relating to an evap line. I don't recall if it was a recall notice of pointed out when I came in for service. I kinda think a recall notice, but that was years ago. It was separate from the filler neck replacement (the old "gas pump keeps shutting off" problem) and a later faulty cap.

 

Yes, the mechanic first ordered one from local Jag dealer then after some trial and error myself decided to order one myself from another dealer using the VIN. Seems to seal fine and get some suction noise when opening the cap to fill.

 

I will check the recalls to see if there is one outstanding.

 

If you run the car almost empty and then fill the car up while it is running, if it has a bad purge valve/lines it should start rough idling/dieseling/bucking before it gets full.