My fellow Jaguar lovers,
Havent been on here in a while, and thats a good thing, still inlove with my Jag.
BUT...
Iv had issues with the gas cas cap. I lost the OEM on and when and got one from an auto parts store, seemed to fit ok but about once a month i get a PO0455 code. i think that might be the problem but i almost **** my self yesterday where i saw rat dropping on the intake manafold.

So guys, should i freak out and start the search for a chewed up hose or just replace the gas cap but this time get it from the dealer?


stay sexy my friends.

 

Rats loooove rubber but they also like a warm engine so not likely in the tail end of the car.
Are you sure the after market cap was the same type? A vented cap versus a non vented. I had a code once for "cap leak", I used a finger full of "vener slider" (vaseline) and it cured the problem.

 

At the the store they gave me 2 diffrent part numbers. they both fit right, im guessing one was vented and the other wasnt, but i still get the code with both. with this new cap it took a lot longer to get the code and it dont happen so frequent.

the code is PO0455 emissions control system leak.

 

It says it is a GROSS EVAP,SYST. LEAK.not a vac leak so I would check all lines to and from the canister. Do you know someone that is willing to barrow you a actual jag cap for a while or swap to see if the problem follows or goes away on either car. Another shot would be to hook up compressed air(no more than 2 or3 LBS) and listen for a air leak all the way back to the tank. It's safe and don't cost.Rig up a pressure gauge in line,turn your regulator all the way out to zero,use caution,don't screw up or you'll blow a line. When you fill up do you try to multi click to get more in? Don't, it pushes fuel into the evap system and you can get stupid codes and it takes a while for the system to clear the excess fuel out.You'd be surprised how much money is wasted diagnosing that because they don't realize what they did.Every time I fill up there are at least one or two people clicking away thinking "a little more"

 

If the code started appearing at the same time you replaced the cap, I would say it is most likely that neither of the aftermarket caps you bought are sealing the system the way the factory cap does.

I would buy a factory cap off eBay or maybe a local junkyard if they have any before digging further into the emissions system.